text: // Copyright 2011 The Chromium Authors. All rights reserved.
  // Use of this source code is governed by a BSD-style license that can be
  // found in the LICENSE file.
  
  #include "config.h"
  
  #include "cc/layer_tree_host_common.h"
  
  #include "cc/content_layer.h"
  #include "cc/content_layer_client.h"
  #include "cc/layer.h"
  #include "cc/layer_animation_controller.h"
  #include "cc/layer_impl.h"
  #include "cc/layer_sorter.h"
  #include "cc/math_util.h"
  #include "cc/proxy.h"
  #include "cc/single_thread_proxy.h"
  #include "cc/test/animation_test_common.h"
  #include "cc/test/geometry_test_utils.h"
  #include "cc/thread.h"
  #include "testing/gmock/include/gmock/gmock.h"
  #include "testing/gtest/include/gtest/gtest.h"
  #include <public/WebTransformationMatrix.h>
  
  using namespace cc;
  using namespace WebKitTests;
  using WebKit::WebTransformationMatrix;
  
  namespace {
  
  template<typename LayerType>
  void setLayerPropertiesForTestingInternal(LayerType* layer, const WebTransformationMatrix& transform, const WebTransformationMatrix& sublayerTransform, const gfx::PointF& anchor, const gfx::PointF& position, const gfx::Size& bounds, bool preserves3D)
  {
      layer->setTransform(transform);
      layer->setSublayerTransform(sublayerTransform);
      layer->setAnchorPoint(anchor);
      layer->setPosition(position);
      layer->setBounds(bounds);
      layer->setPreserves3D(preserves3D);
  }
  
  void setLayerPropertiesForTesting(Layer* layer, const WebTransformationMatrix& transform, const WebTransformationMatrix& sublayerTransform, const gfx::PointF& anchor, const gfx::PointF& position, const gfx::Size& bounds, bool preserves3D)
  {
      setLayerPropertiesForTestingInternal<Layer>(layer, transform, sublayerTransform, anchor, position, bounds, preserves3D);
      layer->setAutomaticallyComputeRasterScale(true);
  }
  
  void setLayerPropertiesForTesting(LayerImpl* layer, const WebTransformationMatrix& transform, const WebTransformationMatrix& sublayerTransform, const gfx::PointF& anchor, const gfx::PointF& position, const gfx::Size& bounds, bool preserves3D)
  {
      setLayerPropertiesForTestingInternal<LayerImpl>(layer, transform, sublayerTransform, anchor, position, bounds, preserves3D);
      layer->setContentBounds(bounds);
  }
  
  void executeCalculateDrawTransformsAndVisibility(Layer* rootLayer, float deviceScaleFactor = 1, float pageScaleFactor = 1)
  {
      WebTransformationMatrix identityMatrix;
      std::vector<scoped_refptr<Layer> > dummyRenderSurfaceLayerList;
      int dummyMaxTextureSize = 512;
      gfx::Size deviceViewportSize = gfx::Size(rootLayer->bounds().width() * deviceScaleFactor, rootLayer->bounds().height() * deviceScaleFactor);
  
      // We are probably not testing what is intended if the rootLayer bounds are empty.
      DCHECK(!rootLayer->bounds().IsEmpty());
      LayerTreeHostCommon::calculateDrawTransforms(rootLayer, deviceViewportSize, deviceScaleFactor, pageScaleFactor, dummyMaxTextureSize, dummyRenderSurfaceLayerList);
  }
  
  void executeCalculateDrawTransformsAndVisibility(LayerImpl* rootLayer, float deviceScaleFactor = 1, float pageScaleFactor = 1)
  {
      // Note: this version skips layer sorting.
  
      WebTransformationMatrix identityMatrix;
      std::vector<LayerImpl*> dummyRenderSurfaceLayerList;
      int dummyMaxTextureSize = 512;
      gfx::Size deviceViewportSize = gfx::Size(rootLayer->bounds().width() * deviceScaleFactor, rootLayer->bounds().height() * deviceScaleFactor);
  
      // We are probably not testing what is intended if the rootLayer bounds are empty.
      DCHECK(!rootLayer->bounds().IsEmpty());
      LayerTreeHostCommon::calculateDrawTransforms(rootLayer, deviceViewportSize, deviceScaleFactor, pageScaleFactor, 0, dummyMaxTextureSize, dummyRenderSurfaceLayerList);
  }
  
  WebTransformationMatrix remove3DComponentOfMatrix(const WebTransformationMatrix& mat)
  {
      WebTransformationMatrix ret = mat;
      ret.setM13(0);
      ret.setM23(0);
      ret.setM31(0);
      ret.setM32(0);
      ret.setM33(1);
      ret.setM34(0);
      ret.setM43(0);
      return ret;
  }
  
  scoped_ptr<LayerImpl> createTreeForFixedPositionTests()
  {
      scoped_ptr<LayerImpl> root = LayerImpl::create(1);
      scoped_ptr<LayerImpl> child = LayerImpl::create(2);
      scoped_ptr<LayerImpl> grandChild = LayerImpl::create(3);
      scoped_ptr<LayerImpl> greatGrandChild = LayerImpl::create(4);
  
      WebTransformationMatrix IdentityMatrix;
      gfx::PointF anchor(0, 0);
      gfx::PointF position(0, 0);
      gfx::Size bounds(100, 100);
      setLayerPropertiesForTesting(root.get(), IdentityMatrix, IdentityMatrix, anchor, position, bounds, false);
      setLayerPropertiesForTesting(child.get(), IdentityMatrix, IdentityMatrix, anchor, position, bounds, false);
      setLayerPropertiesForTesting(grandChild.get(), IdentityMatrix, IdentityMatrix, anchor, position, bounds, false);
      setLayerPropertiesForTesting(greatGrandChild.get(), IdentityMatrix, IdentityMatrix, anchor, position, bounds, false);
  
      grandChild->addChild(greatGrandChild.Pass());
      child->addChild(grandChild.Pass());
      root->addChild(child.Pass());
  
      return root.Pass();
  }
  
  class LayerWithForcedDrawsContent : public Layer {
  public:
      LayerWithForcedDrawsContent()
          : Layer()
      {
      }
  
      virtual bool drawsContent() const OVERRIDE { return true; }
  
  private:
      virtual ~LayerWithForcedDrawsContent()
      {
      }
  };
  
  class MockContentLayerClient : public ContentLayerClient {
  public:
      MockContentLayerClient() { }
      virtual ~MockContentLayerClient() { }
      virtual void paintContents(SkCanvas*, const gfx::Rect& clip, gfx::RectF& opaque) OVERRIDE { }
  };
  
  scoped_refptr<ContentLayer> createDrawableContentLayer(ContentLayerClient* delegate)
  {
      scoped_refptr<ContentLayer> toReturn = ContentLayer::create(delegate);
      toReturn->setIsDrawable(true);
      return toReturn;
  }
  
  #define EXPECT_CONTENTS_SCALE_EQ(expected, layer) \
    do { \
      EXPECT_FLOAT_EQ(expected, layer->contentsScaleX()); \
      EXPECT_FLOAT_EQ(expected, layer->contentsScaleY()); \
    } while (false)
  
  TEST(LayerTreeHostCommonTest, verifyTransformsForNoOpLayer)
  {
      // Sanity check: For layers positioned at zero, with zero size,
      // and with identity transforms, then the drawTransform,
      // screenSpaceTransform, and the hierarchy passed on to children
      // layers should also be identity transforms.
  
      scoped_refptr<Layer> parent = Layer::create();
      scoped_refptr<Layer> child = Layer::create();
      scoped_refptr<Layer> grandChild = Layer::create();
      parent->addChild(child);
      child->addChild(grandChild);
  
      WebTransformationMatrix identityMatrix;
      setLayerPropertiesForTesting(parent.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(100, 100), false);
      setLayerPropertiesForTesting(child.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(0, 0), false);
      setLayerPropertiesForTesting(grandChild.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(0, 0), false);
  
      executeCalculateDrawTransformsAndVisibility(parent.get());
  
      EXPECT_TRANSFORMATION_MATRIX_EQ(identityMatrix, child->drawTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(identityMatrix, child->screenSpaceTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(identityMatrix, grandChild->drawTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(identityMatrix, grandChild->screenSpaceTransform());
  }
  
  TEST(LayerTreeHostCommonTest, verifyTransformsForSingleLayer)
  {
      WebTransformationMatrix identityMatrix;
      scoped_refptr<Layer> layer = Layer::create();
  
      scoped_refptr<Layer> root = Layer::create();
      setLayerPropertiesForTesting(root.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(1, 2), false);
      root->addChild(layer);
  
      // Case 1: setting the sublayer transform should not affect this layer's draw transform or screen-space transform.
      WebTransformationMatrix arbitraryTranslation;
      arbitraryTranslation.translate(10, 20);
      setLayerPropertiesForTesting(layer.get(), identityMatrix, arbitraryTranslation, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(100, 100), false);
      executeCalculateDrawTransformsAndVisibility(root.get());
      WebTransformationMatrix expectedDrawTransform = identityMatrix;
      EXPECT_TRANSFORMATION_MATRIX_EQ(expectedDrawTransform, layer->drawTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(identityMatrix, layer->screenSpaceTransform());
  
      // Case 2: Setting the bounds of the layer should not affect either the draw transform or the screenspace transform.
      WebTransformationMatrix translationToCenter;
      translationToCenter.translate(5, 6);
      setLayerPropertiesForTesting(layer.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(10, 12), false);
      executeCalculateDrawTransformsAndVisibility(root.get());
      EXPECT_TRANSFORMATION_MATRIX_EQ(identityMatrix, layer->drawTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(identityMatrix, layer->screenSpaceTransform());
  
      // Case 3: The anchor point by itself (without a layer transform) should have no effect on the transforms.
      setLayerPropertiesForTesting(layer.get(), identityMatrix, identityMatrix, gfx::PointF(0.25, 0.25), gfx::PointF(0, 0), gfx::Size(10, 12), false);
      executeCalculateDrawTransformsAndVisibility(root.get());
      EXPECT_TRANSFORMATION_MATRIX_EQ(identityMatrix, layer->drawTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(identityMatrix, layer->screenSpaceTransform());
  
      // Case 4: A change in actual position affects both the draw transform and screen space transform.
      WebTransformationMatrix positionTransform;
      positionTransform.translate(0, 1.2);
      setLayerPropertiesForTesting(layer.get(), identityMatrix, identityMatrix, gfx::PointF(0.25, 0.25), gfx::PointF(0, 1.2f), gfx::Size(10, 12), false);
      executeCalculateDrawTransformsAndVisibility(root.get());
      EXPECT_TRANSFORMATION_MATRIX_EQ(positionTransform, layer->drawTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(positionTransform, layer->screenSpaceTransform());
  
      // Case 5: In the correct sequence of transforms, the layer transform should pre-multiply the translationToCenter. This is easily tested by
      //         using a scale transform, because scale and translation are not commutative.
      WebTransformationMatrix layerTransform;
      layerTransform.scale3d(2, 2, 1);
      setLayerPropertiesForTesting(layer.get(), layerTransform, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(10, 12), false);
      executeCalculateDrawTransformsAndVisibility(root.get());
      EXPECT_TRANSFORMATION_MATRIX_EQ(layerTransform, layer->drawTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(layerTransform, layer->screenSpaceTransform());
  
      // Case 6: The layer transform should occur with respect to the anchor point.
      WebTransformationMatrix translationToAnchor;
      translationToAnchor.translate(5, 0);
      WebTransformationMatrix expectedResult = translationToAnchor * layerTransform * translationToAnchor.inverse();
      setLayerPropertiesForTesting(layer.get(), layerTransform, identityMatrix, gfx::PointF(0.5, 0), gfx::PointF(0, 0), gfx::Size(10, 12), false);
      executeCalculateDrawTransformsAndVisibility(root.get());
      EXPECT_TRANSFORMATION_MATRIX_EQ(expectedResult, layer->drawTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(expectedResult, layer->screenSpaceTransform());
  
      // Case 7: Verify that position pre-multiplies the layer transform.
      //         The current implementation of calculateDrawTransforms does this implicitly, but it is
      //         still worth testing to detect accidental regressions.
      expectedResult = positionTransform * translationToAnchor * layerTransform * translationToAnchor.inverse();
      setLayerPropertiesForTesting(layer.get(), layerTransform, identityMatrix, gfx::PointF(0.5, 0), gfx::PointF(0, 1.2f), gfx::Size(10, 12), false);
      executeCalculateDrawTransformsAndVisibility(root.get());
      EXPECT_TRANSFORMATION_MATRIX_EQ(expectedResult, layer->drawTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(expectedResult, layer->screenSpaceTransform());
  }
  
  TEST(LayerTreeHostCommonTest, verifyTransformsForSimpleHierarchy)
  {
      WebTransformationMatrix identityMatrix;
      scoped_refptr<Layer> root = Layer::create();
      scoped_refptr<Layer> parent = Layer::create();
      scoped_refptr<Layer> child = Layer::create();
      scoped_refptr<Layer> grandChild = Layer::create();
      root->addChild(parent);
      parent->addChild(child);
      child->addChild(grandChild);
  
      // One-time setup of root layer
      setLayerPropertiesForTesting(root.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(1, 2), false);
  
      // Case 1: parent's anchorPoint should not affect child or grandChild.
      setLayerPropertiesForTesting(parent.get(), identityMatrix, identityMatrix, gfx::PointF(0.25, 0.25), gfx::PointF(0, 0), gfx::Size(10, 12), false);
      setLayerPropertiesForTesting(child.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(16, 18), false);
      setLayerPropertiesForTesting(grandChild.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(76, 78), false);
      executeCalculateDrawTransformsAndVisibility(root.get());
      EXPECT_TRANSFORMATION_MATRIX_EQ(identityMatrix, child->drawTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(identityMatrix, child->screenSpaceTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(identityMatrix, grandChild->drawTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(identityMatrix, grandChild->screenSpaceTransform());
  
      // Case 2: parent's position affects child and grandChild.
      WebTransformationMatrix parentPositionTransform;
      parentPositionTransform.translate(0, 1.2);
      setLayerPropertiesForTesting(parent.get(), identityMatrix, identityMatrix, gfx::PointF(0.25, 0.25), gfx::PointF(0, 1.2f), gfx::Size(10, 12), false);
      setLayerPropertiesForTesting(child.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(16, 18), false);
      setLayerPropertiesForTesting(grandChild.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(76, 78), false);
      executeCalculateDrawTransformsAndVisibility(root.get());
      EXPECT_TRANSFORMATION_MATRIX_EQ(parentPositionTransform, child->drawTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(parentPositionTransform, child->screenSpaceTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(parentPositionTransform, grandChild->drawTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(parentPositionTransform, grandChild->screenSpaceTransform());
  
      // Case 3: parent's local transform affects child and grandchild
      WebTransformationMatrix parentLayerTransform;
      parentLayerTransform.scale3d(2, 2, 1);
      WebTransformationMatrix parentTranslationToAnchor;
      parentTranslationToAnchor.translate(2.5, 3);
      WebTransformationMatrix parentCompositeTransform = parentTranslationToAnchor * parentLayerTransform * parentTranslationToAnchor.inverse();
      setLayerPropertiesForTesting(parent.get(), parentLayerTransform, identityMatrix, gfx::PointF(0.25, 0.25), gfx::PointF(0, 0), gfx::Size(10, 12), false);
      setLayerPropertiesForTesting(child.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(16, 18), false);
      setLayerPropertiesForTesting(grandChild.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(76, 78), false);
      executeCalculateDrawTransformsAndVisibility(root.get());
      EXPECT_TRANSFORMATION_MATRIX_EQ(parentCompositeTransform, child->drawTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(parentCompositeTransform, child->screenSpaceTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(parentCompositeTransform, grandChild->drawTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(parentCompositeTransform, grandChild->screenSpaceTransform());
  
      // Case 4: parent's sublayerMatrix affects child and grandchild
      //         scaling is used here again so that the correct sequence of transforms is properly tested.
      //         Note that preserves3D is false, but the sublayer matrix should retain its 3D properties when given to child.
      //         But then, the child also does not preserve3D. When it gives its hierarchy to the grandChild, it should be flattened to 2D.
      WebTransformationMatrix parentSublayerMatrix;
      parentSublayerMatrix.scale3d(10, 10, 3.3);
      WebTransformationMatrix parentTranslationToCenter;
      parentTranslationToCenter.translate(5, 6);
      // Sublayer matrix is applied to the center of the parent layer.
      parentCompositeTransform = parentTranslationToAnchor * parentLayerTransform * parentTranslationToAnchor.inverse()
              * parentTranslationToCenter * parentSublayerMatrix * parentTranslationToCenter.inverse();
      WebTransformationMatrix flattenedCompositeTransform = remove3DComponentOfMatrix(parentCompositeTransform);
      setLayerPropertiesForTesting(parent.get(), parentLayerTransform, parentSublayerMatrix, gfx::PointF(0.25, 0.25), gfx::PointF(0, 0), gfx::Size(10, 12), false);
      setLayerPropertiesForTesting(child.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(16, 18), false);
      setLayerPropertiesForTesting(grandChild.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(76, 78), false);
      executeCalculateDrawTransformsAndVisibility(root.get());
      EXPECT_TRANSFORMATION_MATRIX_EQ(parentCompositeTransform, child->drawTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(parentCompositeTransform, child->screenSpaceTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(flattenedCompositeTransform, grandChild->drawTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(flattenedCompositeTransform, grandChild->screenSpaceTransform());
  
      // Case 5: same as Case 4, except that child does preserve 3D, so the grandChild should receive the non-flattened composite transform.
      //
      setLayerPropertiesForTesting(parent.get(), parentLayerTransform, parentSublayerMatrix, gfx::PointF(0.25, 0.25), gfx::PointF(0, 0), gfx::Size(10, 12), false);
      setLayerPropertiesForTesting(child.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(16, 18), true);
      setLayerPropertiesForTesting(grandChild.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(76, 78), false);
      executeCalculateDrawTransformsAndVisibility(root.get());
      EXPECT_TRANSFORMATION_MATRIX_EQ(parentCompositeTransform, child->drawTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(parentCompositeTransform, child->screenSpaceTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(parentCompositeTransform, grandChild->drawTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(parentCompositeTransform, grandChild->screenSpaceTransform());
  }
  
  TEST(LayerTreeHostCommonTest, verifyTransformsForSingleRenderSurface)
  {
      scoped_refptr<Layer> root = Layer::create();
      scoped_refptr<Layer> parent = Layer::create();
      scoped_refptr<Layer> child = Layer::create();
      scoped_refptr<LayerWithForcedDrawsContent> grandChild = make_scoped_refptr(new LayerWithForcedDrawsContent());
      root->addChild(parent);
      parent->addChild(child);
      child->addChild(grandChild);
  
      // One-time setup of root layer
      WebTransformationMatrix identityMatrix;
      setLayerPropertiesForTesting(root.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(1, 2), false);
  
      // Child is set up so that a new render surface should be created.
      child->setOpacity(0.5);
  
      WebTransformationMatrix parentLayerTransform;
      parentLayerTransform.scale3d(1, 0.9, 1);
      WebTransformationMatrix parentTranslationToAnchor;
      parentTranslationToAnchor.translate(25, 30);
      WebTransformationMatrix parentSublayerMatrix;
      parentSublayerMatrix.scale3d(0.9, 1, 3.3);
      WebTransformationMatrix parentTranslationToCenter;
      parentTranslationToCenter.translate(50, 60);
      WebTransformationMatrix parentCompositeTransform = parentTranslationToAnchor * parentLayerTransform * parentTranslationToAnchor.inverse()
              * parentTranslationToCenter * parentSublayerMatrix * parentTranslationToCenter.inverse();
      gfx::Vector2dF parentCompositeScale = MathUtil::computeTransform2dScaleComponents(parentCompositeTransform);
      WebTransformationMatrix surfaceSublayerTransform;
      surfaceSublayerTransform.scaleNonUniform(parentCompositeScale.x(), parentCompositeScale.y());
      WebTransformationMatrix surfaceSublayerCompositeTransform = parentCompositeTransform * surfaceSublayerTransform.inverse();
  
      // Child's render surface should not exist yet.
      ASSERT_FALSE(child->renderSurface());
  
      setLayerPropertiesForTesting(parent.get(), parentLayerTransform, parentSublayerMatrix, gfx::PointF(0.25, 0.25), gfx::PointF(0, 0), gfx::Size(100, 120), false);
      setLayerPropertiesForTesting(child.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(16, 18), false);
      setLayerPropertiesForTesting(grandChild.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(8, 10), false);
      executeCalculateDrawTransformsAndVisibility(root.get());
  
      // Render surface should have been created now.
      ASSERT_TRUE(child->renderSurface());
      ASSERT_EQ(child, child->renderTarget());
  
      // The child layer's draw transform should refer to its new render surface.
      // The screen-space transform, however, should still refer to the root.
      EXPECT_TRANSFORMATION_MATRIX_EQ(surfaceSublayerTransform, child->drawTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(parentCompositeTransform, child->screenSpaceTransform());
  
      // Because the grandChild is the only drawable content, the child's renderSurface will tighten its bounds to the grandChild.
      // The scale at which the surface's subtree is drawn must be removed from the composite transform.
      EXPECT_TRANSFORMATION_MATRIX_EQ(surfaceSublayerCompositeTransform, child->renderTarget()->renderSurface()->drawTransform());
  
      // The screen space is the same as the target since the child surface draws into the root.
      EXPECT_TRANSFORMATION_MATRIX_EQ(surfaceSublayerCompositeTransform, child->renderTarget()->renderSurface()->screenSpaceTransform());
  }
  
  TEST(LayerTreeHostCommonTest, verifyTransformsForReplica)
  {
      scoped_refptr<Layer> root = Layer::create();
      scoped_refptr<Layer> parent = Layer::create();
      scoped_refptr<Layer> child = Layer::create();
      scoped_refptr<Layer> childReplica = Layer::create();
      scoped_refptr<LayerWithForcedDrawsContent> grandChild = make_scoped_refptr(new LayerWithForcedDrawsContent());
      root->addChild(parent);
      parent->addChild(child);
      child->addChild(grandChild);
      child->setReplicaLayer(childReplica.get());
  
      // One-time setup of root layer
      WebTransformationMatrix identityMatrix;
      setLayerPropertiesForTesting(root.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(1, 2), false);
  
      // Child is set up so that a new render surface should be created.
      child->setOpacity(0.5);
  
      WebTransformationMatrix parentLayerTransform;
      parentLayerTransform.scale3d(2, 2, 1);
      WebTransformationMatrix parentTranslationToAnchor;
      parentTranslationToAnchor.translate(2.5, 3);
      WebTransformationMatrix parentSublayerMatrix;
      parentSublayerMatrix.scale3d(10, 10, 3.3);
      WebTransformationMatrix parentTranslationToCenter;
      parentTranslationToCenter.translate(5, 6);
      WebTransformationMatrix parentCompositeTransform = parentTranslationToAnchor * parentLayerTransform * parentTranslationToAnchor.inverse()
              * parentTranslationToCenter * parentSublayerMatrix * parentTranslationToCenter.inverse();
      WebTransformationMatrix childTranslationToCenter;
      childTranslationToCenter.translate(8, 9);
      WebTransformationMatrix replicaLayerTransform;
      replicaLayerTransform.scale3d(3, 3, 1);
      gfx::Vector2dF parentCompositeScale = MathUtil::computeTransform2dScaleComponents(parentCompositeTransform);
      WebTransformationMatrix surfaceSublayerTransform;
      surfaceSublayerTransform.scaleNonUniform(parentCompositeScale.x(), parentCompositeScale.y());
      WebTransformationMatrix replicaCompositeTransform = parentCompositeTransform * replicaLayerTransform * surfaceSublayerTransform.inverse();
  
      // Child's render surface should not exist yet.
      ASSERT_FALSE(child->renderSurface());
  
      setLayerPropertiesForTesting(parent.get(), parentLayerTransform, parentSublayerMatrix, gfx::PointF(0.25, 0.25), gfx::PointF(0, 0), gfx::Size(10, 12), false);
      setLayerPropertiesForTesting(child.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(16, 18), false);
      setLayerPropertiesForTesting(grandChild.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(-0.5, -0.5), gfx::Size(1, 1), false);
      setLayerPropertiesForTesting(childReplica.get(), replicaLayerTransform, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(0, 0), false);
      executeCalculateDrawTransformsAndVisibility(root.get());
  
      // Render surface should have been created now.
      ASSERT_TRUE(child->renderSurface());
      ASSERT_EQ(child, child->renderTarget());
  
      EXPECT_TRANSFORMATION_MATRIX_EQ(replicaCompositeTransform, child->renderTarget()->renderSurface()->replicaDrawTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(replicaCompositeTransform, child->renderTarget()->renderSurface()->replicaScreenSpaceTransform());
  }
  
  TEST(LayerTreeHostCommonTest, verifyTransformsForRenderSurfaceHierarchy)
  {
      // This test creates a more complex tree and verifies it all at once. This covers the following cases:
      //   - layers that are described w.r.t. a render surface: should have draw transforms described w.r.t. that surface
      //   - A render surface described w.r.t. an ancestor render surface: should have a draw transform described w.r.t. that ancestor surface
      //   - Replicas of a render surface are described w.r.t. the replica's transform around its anchor, along with the surface itself.
      //   - Sanity check on recursion: verify transforms of layers described w.r.t. a render surface that is described w.r.t. an ancestor render surface.
      //   - verifying that each layer has a reference to the correct renderSurface and renderTarget values.
  
      scoped_refptr<Layer> root = Layer::create();
      scoped_refptr<Layer> parent = Layer::create();
      scoped_refptr<Layer> renderSurface1 = Layer::create();
      scoped_refptr<Layer> renderSurface2 = Layer::create();
      scoped_refptr<Layer> childOfRoot = Layer::create();
      scoped_refptr<Layer> childOfRS1 = Layer::create();
      scoped_refptr<Layer> childOfRS2 = Layer::create();
      scoped_refptr<Layer> replicaOfRS1 = Layer::create();
      scoped_refptr<Layer> replicaOfRS2 = Layer::create();
      scoped_refptr<Layer> grandChildOfRoot = Layer::create();
      scoped_refptr<LayerWithForcedDrawsContent> grandChildOfRS1 = make_scoped_refptr(new LayerWithForcedDrawsContent());
      scoped_refptr<LayerWithForcedDrawsContent> grandChildOfRS2 = make_scoped_refptr(new LayerWithForcedDrawsContent());
      root->addChild(parent);
      parent->addChild(renderSurface1);
      parent->addChild(childOfRoot);
      renderSurface1->addChild(childOfRS1);
      renderSurface1->addChild(renderSurface2);
      renderSurface2->addChild(childOfRS2);
      childOfRoot->addChild(grandChildOfRoot);
      childOfRS1->addChild(grandChildOfRS1);
      childOfRS2->addChild(grandChildOfRS2);
      renderSurface1->setReplicaLayer(replicaOfRS1.get());
      renderSurface2->setReplicaLayer(replicaOfRS2.get());
  
      // In combination with descendantDrawsContent, opacity != 1 forces the layer to have a new renderSurface.
      renderSurface1->setOpacity(0.5);
      renderSurface2->setOpacity(0.33f);
  
      // One-time setup of root layer
      WebTransformationMatrix identityMatrix;
      setLayerPropertiesForTesting(root.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(1, 2), false);
  
      // All layers in the tree are initialized with an anchor at .25 and a size of (10,10).
      // matrix "A" is the composite layer transform used in all layers, centered about the anchor point
      // matrix "B" is the sublayer transform used in all layers, centered about the center position of the layer.
      // matrix "R" is the composite replica transform used in all replica layers.
      //
      // x component tests that layerTransform and sublayerTransform are done in the right order (translation and scale are noncommutative).
      // y component has a translation by 1 for every ancestor, which indicates the "depth" of the layer in the hierarchy.
      WebTransformationMatrix translationToAnchor;
      translationToAnchor.translate(2.5, 0);
      WebTransformationMatrix translationToCenter;
      translationToCenter.translate(5, 5);
      WebTransformationMatrix layerTransform;
      layerTransform.translate(1, 1);
      WebTransformationMatrix sublayerTransform;
      sublayerTransform.scale3d(10, 1, 1);
      WebTransformationMatrix replicaLayerTransform;
      replicaLayerTransform.scale3d(-2, 5, 1);
  
      WebTransformationMatrix A = translationToAnchor * layerTransform * translationToAnchor.inverse();
      WebTransformationMatrix B = translationToCenter * sublayerTransform * translationToCenter.inverse();
      WebTransformationMatrix R = A * translationToAnchor * replicaLayerTransform * translationToAnchor.inverse();
  
      gfx::Vector2dF surface1ParentTransformScale = MathUtil::computeTransform2dScaleComponents(A * B);
      WebTransformationMatrix surface1SublayerTransform;
      surface1SublayerTransform.scaleNonUniform(surface1ParentTransformScale.x(), surface1ParentTransformScale.y());
  
      // SS1 = transform given to the subtree of renderSurface1
      WebTransformationMatrix SS1 = surface1SublayerTransform;
      // S1 = transform to move from renderSurface1 pixels to the layer space of the owning layer
      WebTransformationMatrix S1 = surface1SublayerTransform.inverse();
  
      gfx::Vector2dF surface2ParentTransformScale = MathUtil::computeTransform2dScaleComponents(SS1 * A * B);
      WebTransformationMatrix surface2SublayerTransform;
      surface2SublayerTransform.scaleNonUniform(surface2ParentTransformScale.x(), surface2ParentTransformScale.y());
  
      // SS2 = transform given to the subtree of renderSurface2
      WebTransformationMatrix SS2 = surface2SublayerTransform;
      // S2 = transform to move from renderSurface2 pixels to the layer space of the owning layer
      WebTransformationMatrix S2 = surface2SublayerTransform.inverse();
  
      setLayerPropertiesForTesting(parent.get(), layerTransform, sublayerTransform, gfx::PointF(0.25, 0), gfx::PointF(0, 0), gfx::Size(10, 10), false);
      setLayerPropertiesForTesting(renderSurface1.get(), layerTransform, sublayerTransform, gfx::PointF(0.25, 0), gfx::PointF(0, 0), gfx::Size(10, 10), false);
      setLayerPropertiesForTesting(renderSurface2.get(), layerTransform, sublayerTransform, gfx::PointF(0.25, 0), gfx::PointF(0, 0), gfx::Size(10, 10), false);
      setLayerPropertiesForTesting(childOfRoot.get(), layerTransform, sublayerTransform, gfx::PointF(0.25, 0), gfx::PointF(0, 0), gfx::Size(10, 10), false);
      setLayerPropertiesForTesting(childOfRS1.get(), layerTransform, sublayerTransform, gfx::PointF(0.25, 0), gfx::PointF(0, 0), gfx::Size(10, 10), false);
      setLayerPropertiesForTesting(childOfRS2.get(), layerTransform, sublayerTransform, gfx::PointF(0.25, 0), gfx::PointF(0, 0), gfx::Size(10, 10), false);
      setLayerPropertiesForTesting(grandChildOfRoot.get(), layerTransform, sublayerTransform, gfx::PointF(0.25, 0), gfx::PointF(0, 0), gfx::Size(10, 10), false);
      setLayerPropertiesForTesting(grandChildOfRS1.get(), layerTransform, sublayerTransform, gfx::PointF(0.25, 0), gfx::PointF(0, 0), gfx::Size(10, 10), false);
      setLayerPropertiesForTesting(grandChildOfRS2.get(), layerTransform, sublayerTransform, gfx::PointF(0.25, 0), gfx::PointF(0, 0), gfx::Size(10, 10), false);
      setLayerPropertiesForTesting(replicaOfRS1.get(), replicaLayerTransform, sublayerTransform, gfx::PointF(0.25, 0), gfx::PointF(0, 0), gfx::Size(), false);
      setLayerPropertiesForTesting(replicaOfRS2.get(), replicaLayerTransform, sublayerTransform, gfx::PointF(0.25, 0), gfx::PointF(0, 0), gfx::Size(), false);
  
      executeCalculateDrawTransformsAndVisibility(root.get());
  
      // Only layers that are associated with render surfaces should have an actual renderSurface() value.
      //
      ASSERT_TRUE(root->renderSurface());
      ASSERT_FALSE(childOfRoot->renderSurface());
      ASSERT_FALSE(grandChildOfRoot->renderSurface());
  
      ASSERT_TRUE(renderSurface1->renderSurface());
      ASSERT_FALSE(childOfRS1->renderSurface());
      ASSERT_FALSE(grandChildOfRS1->renderSurface());
  
      ASSERT_TRUE(renderSurface2->renderSurface());
      ASSERT_FALSE(childOfRS2->renderSurface());
      ASSERT_FALSE(grandChildOfRS2->renderSurface());
  
      // Verify all renderTarget accessors
      //
      EXPECT_EQ(root, parent->renderTarget());
      EXPECT_EQ(root, childOfRoot->renderTarget());
      EXPECT_EQ(root, grandChildOfRoot->renderTarget());
  
      EXPECT_EQ(renderSurface1, renderSurface1->renderTarget());
      EXPECT_EQ(renderSurface1, childOfRS1->renderTarget());
      EXPECT_EQ(renderSurface1, grandChildOfRS1->renderTarget());
  
      EXPECT_EQ(renderSurface2, renderSurface2->renderTarget());
      EXPECT_EQ(renderSurface2, childOfRS2->renderTarget());
      EXPECT_EQ(renderSurface2, grandChildOfRS2->renderTarget());
  
      // Verify layer draw transforms
      //  note that draw transforms are described with respect to the nearest ancestor render surface
      //  but screen space transforms are described with respect to the root.
      //
      EXPECT_TRANSFORMATION_MATRIX_EQ(A, parent->drawTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(A * B * A, childOfRoot->drawTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(A * B * A * B * A, grandChildOfRoot->drawTransform());
  
      EXPECT_TRANSFORMATION_MATRIX_EQ(SS1, renderSurface1->drawTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(SS1 * B * A, childOfRS1->drawTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(SS1 * B * A * B * A, grandChildOfRS1->drawTransform());
  
      EXPECT_TRANSFORMATION_MATRIX_EQ(SS2, renderSurface2->drawTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(SS2 * B * A, childOfRS2->drawTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(SS2 * B * A * B * A, grandChildOfRS2->drawTransform());
  
      // Verify layer screen-space transforms
      //
      EXPECT_TRANSFORMATION_MATRIX_EQ(A, parent->screenSpaceTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(A * B * A, childOfRoot->screenSpaceTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(A * B * A * B * A, grandChildOfRoot->screenSpaceTransform());
  
      EXPECT_TRANSFORMATION_MATRIX_EQ(A * B * A, renderSurface1->screenSpaceTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(A * B * A * B * A, childOfRS1->screenSpaceTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(A * B * A * B * A * B * A, grandChildOfRS1->screenSpaceTransform());
  
      EXPECT_TRANSFORMATION_MATRIX_EQ(A * B * A * B * A, renderSurface2->screenSpaceTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(A * B * A * B * A * B * A, childOfRS2->screenSpaceTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(A * B * A * B * A * B * A * B * A, grandChildOfRS2->screenSpaceTransform());
  
      // Verify render surface transforms.
      //
      // Draw transform of render surface 1 is described with respect to root.
      EXPECT_TRANSFORMATION_MATRIX_EQ(A * B * A * S1, renderSurface1->renderSurface()->drawTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(A * B * R * S1, renderSurface1->renderSurface()->replicaDrawTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(A * B * A * S1, renderSurface1->renderSurface()->screenSpaceTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(A * B * R * S1, renderSurface1->renderSurface()->replicaScreenSpaceTransform());
      // Draw transform of render surface 2 is described with respect to render surface 1.
      EXPECT_TRANSFORMATION_MATRIX_EQ(SS1 * B * A * S2, renderSurface2->renderSurface()->drawTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(SS1 * B * R * S2, renderSurface2->renderSurface()->replicaDrawTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(A * B * A * B * A * S2, renderSurface2->renderSurface()->screenSpaceTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(A * B * A * B * R * S2, renderSurface2->renderSurface()->replicaScreenSpaceTransform());
  
      // Sanity check. If these fail there is probably a bug in the test itself.
      // It is expected that we correctly set up transforms so that the y-component of the screen-space transform
      // encodes the "depth" of the layer in the tree.
      EXPECT_FLOAT_EQ(1, parent->screenSpaceTransform().m42());
      EXPECT_FLOAT_EQ(2, childOfRoot->screenSpaceTransform().m42());
      EXPECT_FLOAT_EQ(3, grandChildOfRoot->screenSpaceTransform().m42());
  
      EXPECT_FLOAT_EQ(2, renderSurface1->screenSpaceTransform().m42());
      EXPECT_FLOAT_EQ(3, childOfRS1->screenSpaceTransform().m42());
      EXPECT_FLOAT_EQ(4, grandChildOfRS1->screenSpaceTransform().m42());
  
      EXPECT_FLOAT_EQ(3, renderSurface2->screenSpaceTransform().m42());
      EXPECT_FLOAT_EQ(4, childOfRS2->screenSpaceTransform().m42());
      EXPECT_FLOAT_EQ(5, grandChildOfRS2->screenSpaceTransform().m42());
  }
  
  TEST(LayerTreeHostCommonTest, verifyTransformsForFlatteningLayer)
  {
      // For layers that flatten their subtree, there should be an orthographic projection
      // (for x and y values) in the middle of the transform sequence. Note that the way the
      // code is currently implemented, it is not expected to use a canonical orthographic
      // projection.
  
      scoped_refptr<Layer> root = Layer::create();
      scoped_refptr<Layer> child = Layer::create();
      scoped_refptr<LayerWithForcedDrawsContent> grandChild = make_scoped_refptr(new LayerWithForcedDrawsContent());
  
      WebTransformationMatrix rotationAboutYAxis;
      rotationAboutYAxis.rotate3d(0, 30, 0);
  
      const WebTransformationMatrix identityMatrix;
      setLayerPropertiesForTesting(root.get(), identityMatrix, identityMatrix, gfx::PointF(), gfx::PointF(), gfx::Size(100, 100), false);
      setLayerPropertiesForTesting(child.get(), rotationAboutYAxis, identityMatrix, gfx::PointF(), gfx::PointF(), gfx::Size(10, 10), false);
      setLayerPropertiesForTesting(grandChild.get(), rotationAboutYAxis, identityMatrix, gfx::PointF(), gfx::PointF(), gfx::Size(10, 10), false);
  
      root->addChild(child);
      child->addChild(grandChild);
      child->setForceRenderSurface(true);
  
      // No layers in this test should preserve 3d.
      ASSERT_FALSE(root->preserves3D());
      ASSERT_FALSE(child->preserves3D());
      ASSERT_FALSE(grandChild->preserves3D());
  
      WebTransformationMatrix expectedChildDrawTransform = rotationAboutYAxis;
      WebTransformationMatrix expectedChildScreenSpaceTransform = rotationAboutYAxis;
      WebTransformationMatrix expectedGrandChildDrawTransform = rotationAboutYAxis; // draws onto child's renderSurface
      WebTransformationMatrix expectedGrandChildScreenSpaceTransform = rotationAboutYAxis.to2dTransform() * rotationAboutYAxis;
  
      executeCalculateDrawTransformsAndVisibility(root.get());
  
      // The child's drawTransform should have been taken by its surface.
      ASSERT_TRUE(child->renderSurface());
      EXPECT_TRANSFORMATION_MATRIX_EQ(expectedChildDrawTransform, child->renderSurface()->drawTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(expectedChildScreenSpaceTransform, child->renderSurface()->screenSpaceTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(identityMatrix, child->drawTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(expectedChildScreenSpaceTransform, child->screenSpaceTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(expectedGrandChildDrawTransform, grandChild->drawTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(expectedGrandChildScreenSpaceTransform, grandChild->screenSpaceTransform());
  }
  
  TEST(LayerTreeHostCommonTest, verifyTransformsForDegenerateIntermediateLayer)
  {
      // A layer that is empty in one axis, but not the other, was accidentally skipping a necessary translation.
      // Without that translation, the coordinate space of the layer's drawTransform is incorrect.
      //
      // Normally this isn't a problem, because the layer wouldn't be drawn anyway, but if that layer becomes a renderSurface, then
      // its drawTransform is implicitly inherited by the rest of the subtree, which then is positioned incorrectly as a result.
  
      scoped_refptr<Layer> root = Layer::create();
      scoped_refptr<Layer> child = Layer::create();
      scoped_refptr<LayerWithForcedDrawsContent> grandChild = make_scoped_refptr(new LayerWithForcedDrawsContent());
  
      // The child height is zero, but has non-zero width that should be accounted for while computing drawTransforms.
      const WebTransformationMatrix identityMatrix;
      setLayerPropertiesForTesting(root.get(), identityMatrix, identityMatrix, gfx::PointF(), gfx::PointF(), gfx::Size(100, 100), false);
      setLayerPropertiesForTesting(child.get(), identityMatrix, identityMatrix, gfx::PointF(), gfx::PointF(), gfx::Size(10, 0), false);
      setLayerPropertiesForTesting(grandChild.get(), identityMatrix, identityMatrix, gfx::PointF(), gfx::PointF(), gfx::Size(10, 10), false);
  
      root->addChild(child);
      child->addChild(grandChild);
      child->setForceRenderSurface(true);
  
      executeCalculateDrawTransformsAndVisibility(root.get());
  
      ASSERT_TRUE(child->renderSurface());
      EXPECT_TRANSFORMATION_MATRIX_EQ(identityMatrix, child->renderSurface()->drawTransform()); // This is the real test, the rest are sanity checks.
      EXPECT_TRANSFORMATION_MATRIX_EQ(identityMatrix, child->drawTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(identityMatrix, grandChild->drawTransform());
  }
  
  TEST(LayerTreeHostCommonTest, verifyRenderSurfaceListForRenderSurfaceWithClippedLayer)
  {
      scoped_refptr<Layer> parent = Layer::create();
      scoped_refptr<Layer> renderSurface1 = Layer::create();
      scoped_refptr<LayerWithForcedDrawsContent> child = make_scoped_refptr(new LayerWithForcedDrawsContent());
  
      const WebTransformationMatrix identityMatrix;
      setLayerPropertiesForTesting(parent.get(), identityMatrix, identityMatrix, gfx::PointF(), gfx::PointF(), gfx::Size(10, 10), false);
      setLayerPropertiesForTesting(renderSurface1.get(), identityMatrix, identityMatrix, gfx::PointF(), gfx::PointF(), gfx::Size(10, 10), false);
      setLayerPropertiesForTesting(child.get(), identityMatrix, identityMatrix, gfx::PointF(), gfx::PointF(30, 30), gfx::Size(10, 10), false);
  
      parent->addChild(renderSurface1);
      parent->setMasksToBounds(true);
      renderSurface1->addChild(child);
      renderSurface1->setForceRenderSurface(true);
  
      std::vector<scoped_refptr<Layer> > renderSurfaceLayerList;
      int dummyMaxTextureSize = 512;
      LayerTreeHostCommon::calculateDrawTransforms(parent.get(), parent->bounds(), 1, 1, dummyMaxTextureSize, renderSurfaceLayerList);
  
      // The child layer's content is entirely outside the parent's clip rect, so the intermediate
      // render surface should not be listed here, even if it was forced to be created. Render surfaces without children or visible
      // content are unexpected at draw time (e.g. we might try to create a content texture of size 0).
      ASSERT_TRUE(parent->renderSurface());
      ASSERT_FALSE(renderSurface1->renderSurface());
      EXPECT_EQ(1U, renderSurfaceLayerList.size());
  }
  
  TEST(LayerTreeHostCommonTest, verifyRenderSurfaceListForTransparentChild)
  {
      scoped_refptr<Layer> parent = Layer::create();
      scoped_refptr<Layer> renderSurface1 = Layer::create();
      scoped_refptr<LayerWithForcedDrawsContent> child = make_scoped_refptr(new LayerWithForcedDrawsContent());
  
      const WebTransformationMatrix identityMatrix;
      setLayerPropertiesForTesting(renderSurface1.get(), identityMatrix, identityMatrix, gfx::PointF(), gfx::PointF(), gfx::Size(10, 10), false);
      setLayerPropertiesForTesting(child.get(), identityMatrix, identityMatrix, gfx::PointF(), gfx::PointF(), gfx::Size(10, 10), false);
  
      parent->addChild(renderSurface1);
      renderSurface1->addChild(child);
      renderSurface1->setForceRenderSurface(true);
      renderSurface1->setOpacity(0);
  
      std::vector<scoped_refptr<Layer> > renderSurfaceLayerList;
      int dummyMaxTextureSize = 512;
      LayerTreeHostCommon::calculateDrawTransforms(parent.get(), parent->bounds(), 1, 1, dummyMaxTextureSize, renderSurfaceLayerList);
  
      // Since the layer is transparent, renderSurface1->renderSurface() should not have gotten added anywhere.
      // Also, the drawable content rect should not have been extended by the children.
      ASSERT_TRUE(parent->renderSurface());
      EXPECT_EQ(0U, parent->renderSurface()->layerList().size());
      EXPECT_EQ(1U, renderSurfaceLayerList.size());
      EXPECT_EQ(parent->id(), renderSurfaceLayerList[0]->id());
      EXPECT_EQ(gfx::Rect(), parent->drawableContentRect());
  }
  
  TEST(LayerTreeHostCommonTest, verifyForceRenderSurface)
  {
      scoped_refptr<Layer> parent = Layer::create();
      scoped_refptr<Layer> renderSurface1 = Layer::create();
      scoped_refptr<LayerWithForcedDrawsContent> child = make_scoped_refptr(new LayerWithForcedDrawsContent());
      renderSurface1->setForceRenderSurface(true);
  
      const WebTransformationMatrix identityMatrix;
      setLayerPropertiesForTesting(parent.get(), identityMatrix, identityMatrix, gfx::PointF(), gfx::PointF(), gfx::Size(10, 10), false);
      setLayerPropertiesForTesting(renderSurface1.get(), identityMatrix, identityMatrix, gfx::PointF(), gfx::PointF(), gfx::Size(10, 10), false);
      setLayerPropertiesForTesting(child.get(), identityMatrix, identityMatrix, gfx::PointF(), gfx::PointF(), gfx::Size(10, 10), false);
  
      parent->addChild(renderSurface1);
      renderSurface1->addChild(child);
  
      // Sanity check before the actual test
      EXPECT_FALSE(parent->renderSurface());
      EXPECT_FALSE(renderSurface1->renderSurface());
  
      std::vector<scoped_refptr<Layer> > renderSurfaceLayerList;
      int dummyMaxTextureSize = 512;
      LayerTreeHostCommon::calculateDrawTransforms(parent.get(), parent->bounds(), 1, 1, dummyMaxTextureSize, renderSurfaceLayerList);
  
      // The root layer always creates a renderSurface
      EXPECT_TRUE(parent->renderSurface());
      EXPECT_TRUE(renderSurface1->renderSurface());
      EXPECT_EQ(2U, renderSurfaceLayerList.size());
  
      renderSurfaceLayerList.clear();
      renderSurface1->setForceRenderSurface(false);
      LayerTreeHostCommon::calculateDrawTransforms(parent.get(), parent->bounds(), 1, 1, dummyMaxTextureSize, renderSurfaceLayerList);
      EXPECT_TRUE(parent->renderSurface());
      EXPECT_FALSE(renderSurface1->renderSurface());
      EXPECT_EQ(1U, renderSurfaceLayerList.size());
  }
  
  TEST(LayerTreeHostCommonTest, verifyScrollCompensationForFixedPositionLayerWithDirectContainer)
  {
      // This test checks for correct scroll compensation when the fixed-position container
      // is the direct parent of the fixed-position layer.
  
      DebugScopedSetImplThread scopedImplThread;
      scoped_ptr<LayerImpl> root = createTreeForFixedPositionTests();
      LayerImpl* child = root->children()[0];
      LayerImpl* grandChild = child->children()[0];
  
      child->setIsContainerForFixedPositionLayers(true);
      grandChild->setFixedToContainerLayer(true);
  
      // Case 1: scrollDelta of 0, 0
      child->setScrollDelta(IntSize(0, 0));
      executeCalculateDrawTransformsAndVisibility(root.get());
  
      WebTransformationMatrix expectedChildTransform;
      WebTransformationMatrix expectedGrandChildTransform = expectedChildTransform;
  
      EXPECT_TRANSFORMATION_MATRIX_EQ(expectedChildTransform, child->drawTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(expectedGrandChildTransform, grandChild->drawTransform());
  
      // Case 2: scrollDelta of 10, 10
      child->setScrollDelta(IntSize(10, 10));
      executeCalculateDrawTransformsAndVisibility(root.get());
  
      // Here the child is affected by scrollDelta, but the fixed position grandChild should not be affected.
      expectedChildTransform.makeIdentity();
      expectedChildTransform.translate(-10, -10);
  
      EXPECT_TRANSFORMATION_MATRIX_EQ(expectedChildTransform, child->drawTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(expectedGrandChildTransform, grandChild->drawTransform());
  }
  
  TEST(LayerTreeHostCommonTest, verifyScrollCompensationForFixedPositionLayerWithTransformedDirectContainer)
  {
      // This test checks for correct scroll compensation when the fixed-position container
      // is the direct parent of the fixed-position layer, but that container is transformed.
      // In this case, the fixed position element inherits the container's transform,
      // but the scrollDelta that has to be undone should not be affected by that transform.
      //
      // Transforms are in general non-commutative; using something like a non-uniform scale
      // helps to verify that translations and non-uniform scales are applied in the correct
      // order.
  
      DebugScopedSetImplThread scopedImplThread;
      scoped_ptr<LayerImpl> root = createTreeForFixedPositionTests();
      LayerImpl* child = root->children()[0];
      LayerImpl* grandChild = child->children()[0];
  
      // This scale will cause child and grandChild to be effectively 200 x 800 with respect to the renderTarget.
      WebTransformationMatrix nonUniformScale;
      nonUniformScale.scaleNonUniform(2, 8);
      child->setTransform(nonUniformScale);
  
      child->setIsContainerForFixedPositionLayers(true);
      grandChild->setFixedToContainerLayer(true);
  
      // Case 1: scrollDelta of 0, 0
      child->setScrollDelta(IntSize(0, 0));
      executeCalculateDrawTransformsAndVisibility(root.get());
  
      WebTransformationMatrix expectedChildTransform;
      expectedChildTransform.multiply(nonUniformScale);
  
      WebTransformationMatrix expectedGrandChildTransform = expectedChildTransform;
  
      EXPECT_TRANSFORMATION_MATRIX_EQ(expectedChildTransform, child->drawTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(expectedGrandChildTransform, grandChild->drawTransform());
  
      // Case 2: scrollDelta of 10, 20
      child->setScrollDelta(IntSize(10, 20));
      executeCalculateDrawTransformsAndVisibility(root.get());
  
      // The child should be affected by scrollDelta, but the fixed position grandChild should not be affected.
      expectedChildTransform.makeIdentity();
      expectedChildTransform.translate(-10, -20); // scrollDelta
      expectedChildTransform.multiply(nonUniformScale);
  
      EXPECT_TRANSFORMATION_MATRIX_EQ(expectedChildTransform, child->drawTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(expectedGrandChildTransform, grandChild->drawTransform());
  }
  
  TEST(LayerTreeHostCommonTest, verifyScrollCompensationForFixedPositionLayerWithDistantContainer)
  {
      // This test checks for correct scroll compensation when the fixed-position container
      // is NOT the direct parent of the fixed-position layer.
      DebugScopedSetImplThread scopedImplThread;
  
      scoped_ptr<LayerImpl> root = createTreeForFixedPositionTests();
      LayerImpl* child = root->children()[0];
      LayerImpl* grandChild = child->children()[0];
      LayerImpl* greatGrandChild = grandChild->children()[0];
  
      child->setIsContainerForFixedPositionLayers(true);
      grandChild->setPosition(gfx::PointF(8, 6));
      greatGrandChild->setFixedToContainerLayer(true);
  
      // Case 1: scrollDelta of 0, 0
      child->setScrollDelta(IntSize(0, 0));
      executeCalculateDrawTransformsAndVisibility(root.get());
  
      WebTransformationMatrix expectedChildTransform;
      WebTransformationMatrix expectedGrandChildTransform;
      expectedGrandChildTransform.translate(8, 6);
  
      WebTransformationMatrix expectedGreatGrandChildTransform = expectedGrandChildTransform;
  
      EXPECT_TRANSFORMATION_MATRIX_EQ(expectedChildTransform, child->drawTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(expectedGrandChildTransform, grandChild->drawTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(expectedGreatGrandChildTransform, greatGrandChild->drawTransform());
  
      // Case 2: scrollDelta of 10, 10
      child->setScrollDelta(IntSize(10, 10));
      executeCalculateDrawTransformsAndVisibility(root.get());
  
      // Here the child and grandChild are affected by scrollDelta, but the fixed position greatGrandChild should not be affected.
      expectedChildTransform.makeIdentity();
      expectedChildTransform.translate(-10, -10);
      expectedGrandChildTransform.makeIdentity();
      expectedGrandChildTransform.translate(-2, -4);
      EXPECT_TRANSFORMATION_MATRIX_EQ(expectedChildTransform, child->drawTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(expectedGrandChildTransform, grandChild->drawTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(expectedGreatGrandChildTransform, greatGrandChild->drawTransform());
  }
  
  TEST(LayerTreeHostCommonTest, verifyScrollCompensationForFixedPositionLayerWithDistantContainerAndTransforms)
  {
      // This test checks for correct scroll compensation when the fixed-position container
      // is NOT the direct parent of the fixed-position layer, and the hierarchy has various
      // transforms that have to be processed in the correct order.
      DebugScopedSetImplThread scopedImplThread;
  
      scoped_ptr<LayerImpl> root = createTreeForFixedPositionTests();
      LayerImpl* child = root->children()[0];
      LayerImpl* grandChild = child->children()[0];
      LayerImpl* greatGrandChild = grandChild->children()[0];
  
      WebTransformationMatrix rotationAboutZ;
      rotationAboutZ.rotate3d(0, 0, 90);
  
      child->setIsContainerForFixedPositionLayers(true);
      child->setTransform(rotationAboutZ);
      grandChild->setPosition(gfx::PointF(8, 6));
      grandChild->setTransform(rotationAboutZ);
      greatGrandChild->setFixedToContainerLayer(true); // greatGrandChild is positioned upside-down with respect to the renderTarget.
  
      // Case 1: scrollDelta of 0, 0
      child->setScrollDelta(IntSize(0, 0));
      executeCalculateDrawTransformsAndVisibility(root.get());
  
      WebTransformationMatrix expectedChildTransform;
      expectedChildTransform.multiply(rotationAboutZ);
  
      WebTransformationMatrix expectedGrandChildTransform;
      expectedGrandChildTransform.multiply(rotationAboutZ); // child's local transform is inherited
      expectedGrandChildTransform.translate(8, 6); // translation because of position occurs before layer's local transform.
      expectedGrandChildTransform.multiply(rotationAboutZ); // grandChild's local transform
  
      WebTransformationMatrix expectedGreatGrandChildTransform = expectedGrandChildTransform;
  
      EXPECT_TRANSFORMATION_MATRIX_EQ(expectedChildTransform, child->drawTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(expectedGrandChildTransform, grandChild->drawTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(expectedGreatGrandChildTransform, greatGrandChild->drawTransform());
  
      // Case 2: scrollDelta of 10, 20
      child->setScrollDelta(IntSize(10, 20));
      executeCalculateDrawTransformsAndVisibility(root.get());
  
      // Here the child and grandChild are affected by scrollDelta, but the fixed position greatGrandChild should not be affected.
      expectedChildTransform.makeIdentity();
      expectedChildTransform.translate(-10, -20); // scrollDelta
      expectedChildTransform.multiply(rotationAboutZ);
  
      expectedGrandChildTransform.makeIdentity();
      expectedGrandChildTransform.translate(-10, -20); // child's scrollDelta is inherited
      expectedGrandChildTransform.multiply(rotationAboutZ); // child's local transform is inherited
      expectedGrandChildTransform.translate(8, 6); // translation because of position occurs before layer's local transform.
      expectedGrandChildTransform.multiply(rotationAboutZ); // grandChild's local transform
  
      EXPECT_TRANSFORMATION_MATRIX_EQ(expectedChildTransform, child->drawTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(expectedGrandChildTransform, grandChild->drawTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(expectedGreatGrandChildTransform, greatGrandChild->drawTransform());
  }
  
  TEST(LayerTreeHostCommonTest, verifyScrollCompensationForFixedPositionLayerWithMultipleScrollDeltas)
  {
      // This test checks for correct scroll compensation when the fixed-position container
      // has multiple ancestors that have nonzero scrollDelta before reaching the space where the layer is fixed.
      // In this test, each scrollDelta occurs in a different space because of each layer's local transform.
      // This test checks for correct scroll compensation when the fixed-position container
      // is NOT the direct parent of the fixed-position layer, and the hierarchy has various
      // transforms that have to be processed in the correct order.
      DebugScopedSetImplThread scopedImplThread;
  
      scoped_ptr<LayerImpl> root = createTreeForFixedPositionTests();
      LayerImpl* child = root->children()[0];
      LayerImpl* grandChild = child->children()[0];
      LayerImpl* greatGrandChild = grandChild->children()[0];
  
      WebTransformationMatrix rotationAboutZ;
      rotationAboutZ.rotate3d(0, 0, 90);
  
      child->setIsContainerForFixedPositionLayers(true);
      child->setTransform(rotationAboutZ);
      grandChild->setPosition(gfx::PointF(8, 6));
      grandChild->setTransform(rotationAboutZ);
      greatGrandChild->setFixedToContainerLayer(true); // greatGrandChild is positioned upside-down with respect to the renderTarget.
  
      // Case 1: scrollDelta of 0, 0
      child->setScrollDelta(IntSize(0, 0));
      executeCalculateDrawTransformsAndVisibility(root.get());
  
      WebTransformationMatrix expectedChildTransform;
      expectedChildTransform.multiply(rotationAboutZ);
  
      WebTransformationMatrix expectedGrandChildTransform;
      expectedGrandChildTransform.multiply(rotationAboutZ); // child's local transform is inherited
      expectedGrandChildTransform.translate(8, 6); // translation because of position occurs before layer's local transform.
      expectedGrandChildTransform.multiply(rotationAboutZ); // grandChild's local transform
  
      WebTransformationMatrix expectedGreatGrandChildTransform = expectedGrandChildTransform;
  
      EXPECT_TRANSFORMATION_MATRIX_EQ(expectedChildTransform, child->drawTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(expectedGrandChildTransform, grandChild->drawTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(expectedGreatGrandChildTransform, greatGrandChild->drawTransform());
  
      // Case 2: scrollDelta of 10, 20
      child->setScrollDelta(IntSize(10, 0));
      grandChild->setScrollDelta(IntSize(5, 0));
      executeCalculateDrawTransformsAndVisibility(root.get());
  
      // Here the child and grandChild are affected by scrollDelta, but the fixed position greatGrandChild should not be affected.
      expectedChildTransform.makeIdentity();
      expectedChildTransform.translate(-10, 0); // scrollDelta
      expectedChildTransform.multiply(rotationAboutZ);
  
      expectedGrandChildTransform.makeIdentity();
      expectedGrandChildTransform.translate(-10, 0); // child's scrollDelta is inherited
      expectedGrandChildTransform.multiply(rotationAboutZ); // child's local transform is inherited
      expectedGrandChildTransform.translate(-5, 0); // grandChild's scrollDelta
      expectedGrandChildTransform.translate(8, 6); // translation because of position occurs before layer's local transform.
      expectedGrandChildTransform.multiply(rotationAboutZ); // grandChild's local transform
  
      EXPECT_TRANSFORMATION_MATRIX_EQ(expectedChildTransform, child->drawTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(expectedGrandChildTransform, grandChild->drawTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(expectedGreatGrandChildTransform, greatGrandChild->drawTransform());
  }
  
  TEST(LayerTreeHostCommonTest, verifyScrollCompensationForFixedPositionLayerWithIntermediateSurfaceAndTransforms)
  {
      // This test checks for correct scroll compensation when the fixed-position container
      // contributes to a different renderSurface than the fixed-position layer. In this
      // case, the surface drawTransforms also have to be accounted for when checking the
      // scrollDelta.
      DebugScopedSetImplThread scopedImplThread;
  
      scoped_ptr<LayerImpl> root = createTreeForFixedPositionTests();
      LayerImpl* child = root->children()[0];
      LayerImpl* grandChild = child->children()[0];
      LayerImpl* greatGrandChild = grandChild->children()[0];
  
      child->setIsContainerForFixedPositionLayers(true);
      grandChild->setPosition(gfx::PointF(8, 6));
      grandChild->setForceRenderSurface(true);
      greatGrandChild->setFixedToContainerLayer(true);
      greatGrandChild->setDrawsContent(true);
  
      WebTransformationMatrix rotationAboutZ;
      rotationAboutZ.rotate3d(0, 0, 90);
      grandChild->setTransform(rotationAboutZ);
  
      // Case 1: scrollDelta of 0, 0
      child->setScrollDelta(IntSize(0, 0));
      executeCalculateDrawTransformsAndVisibility(root.get());
  
      WebTransformationMatrix expectedChildTransform;
      WebTransformationMatrix expectedSurfaceDrawTransform;
      expectedSurfaceDrawTransform.translate(8, 6);
      expectedSurfaceDrawTransform.multiply(rotationAboutZ);
      WebTransformationMatrix expectedGrandChildTransform;
      WebTransformationMatrix expectedGreatGrandChildTransform;
      ASSERT_TRUE(grandChild->renderSurface());
      EXPECT_TRANSFORMATION_MATRIX_EQ(expectedChildTransform, child->drawTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(expectedSurfaceDrawTransform, grandChild->renderSurface()->drawTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(expectedGrandChildTransform, grandChild->drawTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(expectedGreatGrandChildTransform, greatGrandChild->drawTransform());
  
      // Case 2: scrollDelta of 10, 30
      child->setScrollDelta(IntSize(10, 30));
      executeCalculateDrawTransformsAndVisibility(root.get());
  
      // Here the grandChild remains unchanged, because it scrolls along with the
      // renderSurface, and the translation is actually in the renderSurface. But, the fixed
      // position greatGrandChild is more awkward: its actually being drawn with respect to
      // the renderSurface, but it needs to remain fixed with resepct to a container beyond
      // that surface. So, the net result is that, unlike previous tests where the fixed
      // position layer's transform remains unchanged, here the fixed position layer's
      // transform explicitly contains the translation that cancels out the scroll.
      expectedChildTransform.makeIdentity();
      expectedChildTransform.translate(-10, -30); // scrollDelta
  
      expectedSurfaceDrawTransform.makeIdentity();
      expectedSurfaceDrawTransform.translate(-10, -30); // scrollDelta
      expectedSurfaceDrawTransform.translate(8, 6);
      expectedSurfaceDrawTransform.multiply(rotationAboutZ);
  
      // The rotation and its inverse are needed to place the scrollDelta compensation in
      // the correct space. This test will fail if the rotation/inverse are backwards, too,
      // so it requires perfect order of operations.
      expectedGreatGrandChildTransform.makeIdentity();
      expectedGreatGrandChildTransform.multiply(rotationAboutZ.inverse());
      expectedGreatGrandChildTransform.translate(10, 30); // explicit canceling out the scrollDelta that gets embedded in the fixed position layer's surface.
      expectedGreatGrandChildTransform.multiply(rotationAboutZ);
  
      ASSERT_TRUE(grandChild->renderSurface());
      EXPECT_TRANSFORMATION_MATRIX_EQ(expectedChildTransform, child->drawTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(expectedSurfaceDrawTransform, grandChild->renderSurface()->drawTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(expectedGrandChildTransform, grandChild->drawTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(expectedGreatGrandChildTransform, greatGrandChild->drawTransform());
  }
  
  TEST(LayerTreeHostCommonTest, verifyScrollCompensationForFixedPositionLayerWithMultipleIntermediateSurfaces)
  {
      // This test checks for correct scroll compensation when the fixed-position container
      // contributes to a different renderSurface than the fixed-position layer, with
      // additional renderSurfaces in-between. This checks that the conversion to ancestor
      // surfaces is accumulated properly in the final matrix transform.
      DebugScopedSetImplThread scopedImplThread;
  
      scoped_ptr<LayerImpl> root = createTreeForFixedPositionTests();
      LayerImpl* child = root->children()[0];
      LayerImpl* grandChild = child->children()[0];
      LayerImpl* greatGrandChild = grandChild->children()[0];
  
      // Add one more layer to the test tree for this scenario.
      {
          WebTransformationMatrix identity;
          scoped_ptr<LayerImpl> fixedPositionChild = LayerImpl::create(5);
          setLayerPropertiesForTesting(fixedPositionChild.get(), identity, identity, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(100, 100), false);
          greatGrandChild->addChild(fixedPositionChild.Pass());
      }
      LayerImpl* fixedPositionChild = greatGrandChild->children()[0];
  
      // Actually set up the scenario here.
      child->setIsContainerForFixedPositionLayers(true);
      grandChild->setPosition(gfx::PointF(8, 6));
      grandChild->setForceRenderSurface(true);
      greatGrandChild->setPosition(gfx::PointF(40, 60));
      greatGrandChild->setForceRenderSurface(true);
      fixedPositionChild->setFixedToContainerLayer(true);
      fixedPositionChild->setDrawsContent(true);
  
      // The additional rotations, which are non-commutative with translations, help to
      // verify that we have correct order-of-operations in the final scroll compensation.
      // Note that rotating about the center of the layer ensures we do not accidentally
      // clip away layers that we want to test.
      WebTransformationMatrix rotationAboutZ;
      rotationAboutZ.translate(50, 50);
      rotationAboutZ.rotate3d(0, 0, 90);
      rotationAboutZ.translate(-50, -50);
      grandChild->setTransform(rotationAboutZ);
      greatGrandChild->setTransform(rotationAboutZ);
  
      // Case 1: scrollDelta of 0, 0
      child->setScrollDelta(IntSize(0, 0));
      executeCalculateDrawTransformsAndVisibility(root.get());
  
      WebTransformationMatrix expectedChildTransform;
  
      WebTransformationMatrix expectedGrandChildSurfaceDrawTransform;
      expectedGrandChildSurfaceDrawTransform.translate(8, 6);
      expectedGrandChildSurfaceDrawTransform.multiply(rotationAboutZ);
  
      WebTransformationMatrix expectedGrandChildTransform;
  
      WebTransformationMatrix expectedGreatGrandChildSurfaceDrawTransform;
      expectedGreatGrandChildSurfaceDrawTransform.translate(40, 60);
      expectedGreatGrandChildSurfaceDrawTransform.multiply(rotationAboutZ);
  
      WebTransformationMatrix expectedGreatGrandChildTransform;
  
      WebTransformationMatrix expectedFixedPositionChildTransform;
  
      ASSERT_TRUE(grandChild->renderSurface());
      ASSERT_TRUE(greatGrandChild->renderSurface());
      EXPECT_TRANSFORMATION_MATRIX_EQ(expectedChildTransform, child->drawTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(expectedGrandChildSurfaceDrawTransform, grandChild->renderSurface()->drawTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(expectedGrandChildTransform, grandChild->drawTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(expectedGreatGrandChildSurfaceDrawTransform, greatGrandChild->renderSurface()->drawTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(expectedGreatGrandChildTransform, greatGrandChild->drawTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(expectedFixedPositionChildTransform, fixedPositionChild->drawTransform());
  
      // Case 2: scrollDelta of 10, 30
      child->setScrollDelta(IntSize(10, 30));
      executeCalculateDrawTransformsAndVisibility(root.get());
  
      expectedChildTransform.makeIdentity();
      expectedChildTransform.translate(-10, -30); // scrollDelta
  
      expectedGrandChildSurfaceDrawTransform.makeIdentity();
      expectedGrandChildSurfaceDrawTransform.translate(-10, -30); // scrollDelta
      expectedGrandChildSurfaceDrawTransform.translate(8, 6);
      expectedGrandChildSurfaceDrawTransform.multiply(rotationAboutZ);
  
      // grandChild, greatGrandChild, and greatGrandChild's surface are not expected to
      // change, since they are all not fixed, and they are all drawn with respect to
      // grandChild's surface that already has the scrollDelta accounted for.
  
      // But the great-great grandchild, "fixedPositionChild", should have a transform that explicitly cancels out the scrollDelta.
      // The expected transform is:
      //   compoundDrawTransform.inverse() * translate(positive scrollDelta) * compoundOriginTransform
      WebTransformationMatrix compoundDrawTransform; // transform from greatGrandChildSurface's origin to the root surface.
      compoundDrawTransform.translate(8, 6); // origin translation of grandChild
      compoundDrawTransform.multiply(rotationAboutZ); // rotation of grandChild
      compoundDrawTransform.translate(40, 60); // origin translation of greatGrandChild
      compoundDrawTransform.multiply(rotationAboutZ); // rotation of greatGrandChild
  
      expectedFixedPositionChildTransform.makeIdentity();
      expectedFixedPositionChildTransform.multiply(compoundDrawTransform.inverse());
      expectedFixedPositionChildTransform.translate(10, 30); // explicit canceling out the scrollDelta that gets embedded in the fixed position layer's surface.
      expectedFixedPositionChildTransform.multiply(compoundDrawTransform);
  
      ASSERT_TRUE(grandChild->renderSurface());
      ASSERT_TRUE(greatGrandChild->renderSurface());
      EXPECT_TRANSFORMATION_MATRIX_EQ(expectedChildTransform, child->drawTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(expectedGrandChildSurfaceDrawTransform, grandChild->renderSurface()->drawTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(expectedGrandChildTransform, grandChild->drawTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(expectedGreatGrandChildSurfaceDrawTransform, greatGrandChild->renderSurface()->drawTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(expectedGreatGrandChildTransform, greatGrandChild->drawTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(expectedFixedPositionChildTransform, fixedPositionChild->drawTransform());
  }
  
  TEST(LayerTreeHostCommonTest, verifyScrollCompensationForFixedPositionLayerWithContainerLayerThatHasSurface)
  {
      // This test checks for correct scroll compensation when the fixed-position container
      // itself has a renderSurface. In this case, the container layer should be treated
      // like a layer that contributes to a renderTarget, and that renderTarget
      // is completely irrelevant; it should not affect the scroll compensation.
      DebugScopedSetImplThread scopedImplThread;
  
      scoped_ptr<LayerImpl> root = createTreeForFixedPositionTests();
      LayerImpl* child = root->children()[0];
      LayerImpl* grandChild = child->children()[0];
  
      child->setIsContainerForFixedPositionLayers(true);
      child->setForceRenderSurface(true);
      grandChild->setFixedToContainerLayer(true);
      grandChild->setDrawsContent(true);
  
      // Case 1: scrollDelta of 0, 0
      child->setScrollDelta(IntSize(0, 0));
      executeCalculateDrawTransformsAndVisibility(root.get());
  
      WebTransformationMatrix expectedSurfaceDrawTransform;
      expectedSurfaceDrawTransform.translate(0, 0);
      WebTransformationMatrix expectedChildTransform;
      WebTransformationMatrix expectedGrandChildTransform;
      ASSERT_TRUE(child->renderSurface());
      EXPECT_TRANSFORMATION_MATRIX_EQ(expectedSurfaceDrawTransform, child->renderSurface()->drawTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(expectedChildTransform, child->drawTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(expectedGrandChildTransform, grandChild->drawTransform());
  
      // Case 2: scrollDelta of 10, 10
      child->setScrollDelta(IntSize(10, 10));
      executeCalculateDrawTransformsAndVisibility(root.get());
  
      // The surface is translated by scrollDelta, the child transform doesn't change
      // because it scrolls along with the surface, but the fixed position grandChild
      // needs to compensate for the scroll translation.
      expectedSurfaceDrawTransform.makeIdentity();
      expectedSurfaceDrawTransform.translate(-10, -10);
      expectedGrandChildTransform.makeIdentity();
      expectedGrandChildTransform.translate(10, 10);
  
      ASSERT_TRUE(child->renderSurface());
      EXPECT_TRANSFORMATION_MATRIX_EQ(expectedSurfaceDrawTransform, child->renderSurface()->drawTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(expectedChildTransform, child->drawTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(expectedGrandChildTransform, grandChild->drawTransform());
  }
  
  TEST(LayerTreeHostCommonTest, verifyScrollCompensationForFixedPositionLayerThatIsAlsoFixedPositionContainer)
  {
      // This test checks the scenario where a fixed-position layer also happens to be a
      // container itself for a descendant fixed position layer. In particular, the layer
      // should not accidentally be fixed to itself.
      DebugScopedSetImplThread scopedImplThread;
  
      scoped_ptr<LayerImpl> root = createTreeForFixedPositionTests();
      LayerImpl* child = root->children()[0];
      LayerImpl* grandChild = child->children()[0];
  
      child->setIsContainerForFixedPositionLayers(true);
      grandChild->setFixedToContainerLayer(true);
  
      // This should not confuse the grandChild. If correct, the grandChild would still be considered fixed to its container (i.e. "child").
      grandChild->setIsContainerForFixedPositionLayers(true);
  
      // Case 1: scrollDelta of 0, 0
      child->setScrollDelta(IntSize(0, 0));
      executeCalculateDrawTransformsAndVisibility(root.get());
  
      WebTransformationMatrix expectedChildTransform;
      WebTransformationMatrix expectedGrandChildTransform;
      EXPECT_TRANSFORMATION_MATRIX_EQ(expectedChildTransform, child->drawTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(expectedGrandChildTransform, grandChild->drawTransform());
  
      // Case 2: scrollDelta of 10, 10
      child->setScrollDelta(IntSize(10, 10));
      executeCalculateDrawTransformsAndVisibility(root.get());
  
      // Here the child is affected by scrollDelta, but the fixed position grandChild should not be affected.
      expectedChildTransform.makeIdentity();
      expectedChildTransform.translate(-10, -10);
      EXPECT_TRANSFORMATION_MATRIX_EQ(expectedChildTransform, child->drawTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(expectedGrandChildTransform, grandChild->drawTransform());
  }
  
  TEST(LayerTreeHostCommonTest, verifyScrollCompensationForFixedPositionLayerThatHasNoContainer)
  {
      // This test checks scroll compensation when a fixed-position layer does not find any
      // ancestor that is a "containerForFixedPositionLayers". In this situation, the layer should
      // be fixed to the viewport -- not the rootLayer, which may have transforms of its own.
      DebugScopedSetImplThread scopedImplThread;
  
      scoped_ptr<LayerImpl> root = createTreeForFixedPositionTests();
      LayerImpl* child = root->children()[0];
      LayerImpl* grandChild = child->children()[0];
  
      WebTransformationMatrix rotationByZ;
      rotationByZ.rotate3d(0, 0, 90);
  
      root->setTransform(rotationByZ);
      grandChild->setFixedToContainerLayer(true);
  
      // Case 1: root scrollDelta of 0, 0
      root->setScrollDelta(IntSize(0, 0));
      executeCalculateDrawTransformsAndVisibility(root.get());
  
      WebTransformationMatrix identityMatrix;
  
      EXPECT_TRANSFORMATION_MATRIX_EQ(identityMatrix, child->drawTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(identityMatrix, grandChild->drawTransform());
  
      // Case 2: root scrollDelta of 10, 10
      root->setScrollDelta(IntSize(10, 20));
      executeCalculateDrawTransformsAndVisibility(root.get());
  
      // The child is affected by scrollDelta, but it is already implcitly accounted for by
      // the child's target surface (i.e. the root renderSurface). The grandChild is not
      // affected by the scrollDelta, so its drawTransform needs to explicitly
      // inverse-compensate for the scroll that's embedded in the target surface.
      WebTransformationMatrix expectedGrandChildTransform;
      expectedGrandChildTransform.multiply(rotationByZ.inverse());
      expectedGrandChildTransform.translate(10, 20); // explicit canceling out the scrollDelta that gets embedded in the fixed position layer's surface.
      expectedGrandChildTransform.multiply(rotationByZ);
  
      EXPECT_TRANSFORMATION_MATRIX_EQ(identityMatrix, child->drawTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(expectedGrandChildTransform, grandChild->drawTransform());
  }
  
  TEST(LayerTreeHostCommonTest, verifyClipRectCullsRenderSurfaces)
  {
      // The entire subtree of layers that are outside the clipRect should be culled away,
      // and should not affect the renderSurfaceLayerList.
      //
      // The test tree is set up as follows:
      //  - all layers except the leafNodes are forced to be a new renderSurface that have something to draw.
      //  - parent is a large container layer.
      //  - child has masksToBounds=true to cause clipping.
      //  - grandChild is positioned outside of the child's bounds
      //  - greatGrandChild is also kept outside child's bounds.
      //
      // In this configuration, grandChild and greatGrandChild are completely outside the
      // clipRect, and they should never get scheduled on the list of renderSurfaces.
      //
  
      const WebTransformationMatrix identityMatrix;
      scoped_refptr<Layer> parent = Layer::create();
      scoped_refptr<Layer> child = Layer::create();
      scoped_refptr<Layer> grandChild = Layer::create();
      scoped_refptr<Layer> greatGrandChild = Layer::create();
      scoped_refptr<LayerWithForcedDrawsContent> leafNode1 = make_scoped_refptr(new LayerWithForcedDrawsContent());
      scoped_refptr<LayerWithForcedDrawsContent> leafNode2 = make_scoped_refptr(new LayerWithForcedDrawsContent());
      parent->addChild(child);
      child->addChild(grandChild);
      grandChild->addChild(greatGrandChild);
  
      // leafNode1 ensures that parent and child are kept on the renderSurfaceLayerList,
      // even though grandChild and greatGrandChild should be clipped.
      child->addChild(leafNode1);
      greatGrandChild->addChild(leafNode2);
  
      setLayerPropertiesForTesting(parent.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(500, 500), false);
      setLayerPropertiesForTesting(child.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(20, 20), false);
      setLayerPropertiesForTesting(grandChild.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(45, 45), gfx::Size(10, 10), false);
      setLayerPropertiesForTesting(greatGrandChild.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(10, 10), false);
      setLayerPropertiesForTesting(leafNode1.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(500, 500), false);
      setLayerPropertiesForTesting(leafNode2.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(20, 20), false);
  
      child->setMasksToBounds(true);
      child->setOpacity(0.4f);
      grandChild->setOpacity(0.5);
      greatGrandChild->setOpacity(0.4f);
  
      std::vector<scoped_refptr<Layer> > renderSurfaceLayerList;
      int dummyMaxTextureSize = 512;
      LayerTreeHostCommon::calculateDrawTransforms(parent.get(), parent->bounds(), 1, 1, dummyMaxTextureSize, renderSurfaceLayerList);
  
      ASSERT_EQ(2U, renderSurfaceLayerList.size());
      EXPECT_EQ(parent->id(), renderSurfaceLayerList[0]->id());
      EXPECT_EQ(child->id(), renderSurfaceLayerList[1]->id());
  }
  
  TEST(LayerTreeHostCommonTest, verifyClipRectCullsSurfaceWithoutVisibleContent)
  {
      // When a renderSurface has a clipRect, it is used to clip the contentRect
      // of the surface. When the renderSurface is animating its transforms, then
      // the contentRect's position in the clipRect is not defined on the main
      // thread, and its contentRect should not be clipped.
  
      // The test tree is set up as follows:
      //  - parent is a container layer that masksToBounds=true to cause clipping.
      //  - child is a renderSurface, which has a clipRect set to the bounds of the parent.
      //  - grandChild is a renderSurface, and the only visible content in child. It is positioned outside of the clipRect from parent.
  
      // In this configuration, grandChild should be outside the clipped
      // contentRect of the child, making grandChild not appear in the
      // renderSurfaceLayerList. However, when we place an animation on the child,
      // this clipping should be avoided and we should keep the grandChild
      // in the renderSurfaceLayerList.
  
      const WebTransformationMatrix identityMatrix;
      scoped_refptr<Layer> parent = Layer::create();
      scoped_refptr<Layer> child = Layer::create();
      scoped_refptr<Layer> grandChild = Layer::create();
      scoped_refptr<LayerWithForcedDrawsContent> leafNode = make_scoped_refptr(new LayerWithForcedDrawsContent());
      parent->addChild(child);
      child->addChild(grandChild);
      grandChild->addChild(leafNode);
  
      setLayerPropertiesForTesting(parent.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(100, 100), false);
      setLayerPropertiesForTesting(child.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(20, 20), false);
      setLayerPropertiesForTesting(grandChild.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(200, 200), gfx::Size(10, 10), false);
      setLayerPropertiesForTesting(leafNode.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(10, 10), false);
  
      parent->setMasksToBounds(true);
      child->setOpacity(0.4f);
      grandChild->setOpacity(0.4f);
  
      std::vector<scoped_refptr<Layer> > renderSurfaceLayerList;
      int dummyMaxTextureSize = 512;
      LayerTreeHostCommon::calculateDrawTransforms(parent.get(), parent->bounds(), 1, 1, dummyMaxTextureSize, renderSurfaceLayerList);
  
      // Without an animation, we should cull child and grandChild from the renderSurfaceLayerList.
      ASSERT_EQ(1U, renderSurfaceLayerList.size());
      EXPECT_EQ(parent->id(), renderSurfaceLayerList[0]->id());
  
      // Now put an animating transform on child.
      addAnimatedTransformToController(*child->layerAnimationController(), 10, 30, 0);
  
      parent->clearRenderSurface();
      child->clearRenderSurface();
      grandChild->clearRenderSurface();
      renderSurfaceLayerList.clear();
  
      LayerTreeHostCommon::calculateDrawTransforms(parent.get(), parent->bounds(), 1, 1, dummyMaxTextureSize, renderSurfaceLayerList);
  
      // With an animating transform, we should keep child and grandChild in the renderSurfaceLayerList.
      ASSERT_EQ(3U, renderSurfaceLayerList.size());
      EXPECT_EQ(parent->id(), renderSurfaceLayerList[0]->id());
      EXPECT_EQ(child->id(), renderSurfaceLayerList[1]->id());
      EXPECT_EQ(grandChild->id(), renderSurfaceLayerList[2]->id());
  }
  
  TEST(LayerTreeHostCommonTest, verifyDrawableContentRectForLayers)
  {
      // Verify that layers get the appropriate drawableContentRect when their parent masksToBounds is true.
      //
      //   grandChild1 - completely inside the region; drawableContentRect should be the layer rect expressed in target space.
      //   grandChild2 - partially clipped but NOT masksToBounds; the clipRect will be the intersection of layerBounds and the mask region.
      //   grandChild3 - partially clipped and masksToBounds; the drawableContentRect will still be the intersection of layerBounds and the mask region.
      //   grandChild4 - outside parent's clipRect; the drawableContentRect should be empty.
      //
  
      const WebTransformationMatrix identityMatrix;
      scoped_refptr<Layer> parent = Layer::create();
      scoped_refptr<Layer> child = Layer::create();
      scoped_refptr<Layer> grandChild1 = Layer::create();
      scoped_refptr<Layer> grandChild2 = Layer::create();
      scoped_refptr<Layer> grandChild3 = Layer::create();
      scoped_refptr<Layer> grandChild4 = Layer::create();
  
      parent->addChild(child);
      child->addChild(grandChild1);
      child->addChild(grandChild2);
      child->addChild(grandChild3);
      child->addChild(grandChild4);
  
      setLayerPropertiesForTesting(parent.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(500, 500), false);
      setLayerPropertiesForTesting(child.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(20, 20), false);
      setLayerPropertiesForTesting(grandChild1.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(5, 5), gfx::Size(10, 10), false);
      setLayerPropertiesForTesting(grandChild2.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(15, 15), gfx::Size(10, 10), false);
      setLayerPropertiesForTesting(grandChild3.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(15, 15), gfx::Size(10, 10), false);
      setLayerPropertiesForTesting(grandChild4.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(45, 45), gfx::Size(10, 10), false);
  
      child->setMasksToBounds(true);
      grandChild3->setMasksToBounds(true);
  
      // Force everyone to be a render surface.
      child->setOpacity(0.4f);
      grandChild1->setOpacity(0.5);
      grandChild2->setOpacity(0.5);
      grandChild3->setOpacity(0.5);
      grandChild4->setOpacity(0.5);
  
      std::vector<scoped_refptr<Layer> > renderSurfaceLayerList;
      int dummyMaxTextureSize = 512;
      LayerTreeHostCommon::calculateDrawTransforms(parent.get(), parent->bounds(), 1, 1, dummyMaxTextureSize, renderSurfaceLayerList);
  
      EXPECT_RECT_EQ(gfx::Rect(gfx::Point(5, 5), gfx::Size(10, 10)), grandChild1->drawableContentRect());
      EXPECT_RECT_EQ(gfx::Rect(gfx::Point(15, 15), gfx::Size(5, 5)), grandChild3->drawableContentRect());
      EXPECT_RECT_EQ(gfx::Rect(gfx::Point(15, 15), gfx::Size(5, 5)), grandChild3->drawableContentRect());
      EXPECT_TRUE(grandChild4->drawableContentRect().IsEmpty());
  }
  
  TEST(LayerTreeHostCommonTest, verifyClipRectIsPropagatedCorrectlyToSurfaces)
  {
      // Verify that renderSurfaces (and their layers) get the appropriate clipRects when their parent masksToBounds is true.
      //
      // Layers that own renderSurfaces (at least for now) do not inherit any clipping;
      // instead the surface will enforce the clip for the entire subtree. They may still
      // have a clipRect of their own layer bounds, however, if masksToBounds was true.
      //
  
      const WebTransformationMatrix identityMatrix;
      scoped_refptr<Layer> parent = Layer::create();
      scoped_refptr<Layer> child = Layer::create();
      scoped_refptr<Layer> grandChild1 = Layer::create();
      scoped_refptr<Layer> grandChild2 = Layer::create();
      scoped_refptr<Layer> grandChild3 = Layer::create();
      scoped_refptr<Layer> grandChild4 = Layer::create();
      scoped_refptr<LayerWithForcedDrawsContent> leafNode1 = make_scoped_refptr(new LayerWithForcedDrawsContent());
      scoped_refptr<LayerWithForcedDrawsContent> leafNode2 = make_scoped_refptr(new LayerWithForcedDrawsContent());
      scoped_refptr<LayerWithForcedDrawsContent> leafNode3 = make_scoped_refptr(new LayerWithForcedDrawsContent());
      scoped_refptr<LayerWithForcedDrawsContent> leafNode4 = make_scoped_refptr(new LayerWithForcedDrawsContent());
  
      parent->addChild(child);
      child->addChild(grandChild1);
      child->addChild(grandChild2);
      child->addChild(grandChild3);
      child->addChild(grandChild4);
  
      // the leaf nodes ensure that these grandChildren become renderSurfaces for this test.
      grandChild1->addChild(leafNode1);
      grandChild2->addChild(leafNode2);
      grandChild3->addChild(leafNode3);
      grandChild4->addChild(leafNode4);
  
      setLayerPropertiesForTesting(parent.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(500, 500), false);
      setLayerPropertiesForTesting(child.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(20, 20), false);
      setLayerPropertiesForTesting(grandChild1.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(5, 5), gfx::Size(10, 10), false);
      setLayerPropertiesForTesting(grandChild2.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(15, 15), gfx::Size(10, 10), false);
      setLayerPropertiesForTesting(grandChild3.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(15, 15), gfx::Size(10, 10), false);
      setLayerPropertiesForTesting(grandChild4.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(45, 45), gfx::Size(10, 10), false);
      setLayerPropertiesForTesting(leafNode1.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(10, 10), false);
      setLayerPropertiesForTesting(leafNode2.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(10, 10), false);
      setLayerPropertiesForTesting(leafNode3.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(10, 10), false);
      setLayerPropertiesForTesting(leafNode4.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(10, 10), false);
  
      child->setMasksToBounds(true);
      grandChild3->setMasksToBounds(true);
      grandChild4->setMasksToBounds(true);
  
      // Force everyone to be a render surface.
      child->setOpacity(0.4f);
      grandChild1->setOpacity(0.5);
      grandChild2->setOpacity(0.5);
      grandChild3->setOpacity(0.5);
      grandChild4->setOpacity(0.5);
  
      std::vector<scoped_refptr<Layer> > renderSurfaceLayerList;
      int dummyMaxTextureSize = 512;
      LayerTreeHostCommon::calculateDrawTransforms(parent.get(), parent->bounds(), 1, 1, dummyMaxTextureSize, renderSurfaceLayerList);
  
      ASSERT_TRUE(grandChild1->renderSurface());
      ASSERT_TRUE(grandChild2->renderSurface());
      ASSERT_TRUE(grandChild3->renderSurface());
      EXPECT_FALSE(grandChild4->renderSurface()); // Because grandChild4 is entirely clipped, it is expected to not have a renderSurface.
  
      // Surfaces are clipped by their parent, but un-affected by the owning layer's masksToBounds.
      EXPECT_RECT_EQ(gfx::Rect(gfx::Point(0, 0), gfx::Size(20, 20)), grandChild1->renderSurface()->clipRect());
      EXPECT_RECT_EQ(gfx::Rect(gfx::Point(0, 0), gfx::Size(20, 20)), grandChild2->renderSurface()->clipRect());
      EXPECT_RECT_EQ(gfx::Rect(gfx::Point(0, 0), gfx::Size(20, 20)), grandChild3->renderSurface()->clipRect());
  }
  
  TEST(LayerTreeHostCommonTest, verifyAnimationsForRenderSurfaceHierarchy)
  {
      scoped_refptr<Layer> parent = Layer::create();
      scoped_refptr<Layer> renderSurface1 = Layer::create();
      scoped_refptr<Layer> renderSurface2 = Layer::create();
      scoped_refptr<Layer> childOfRoot = Layer::create();
      scoped_refptr<Layer> childOfRS1 = Layer::create();
      scoped_refptr<Layer> childOfRS2 = Layer::create();
      scoped_refptr<Layer> grandChildOfRoot = Layer::create();
      scoped_refptr<LayerWithForcedDrawsContent> grandChildOfRS1 = make_scoped_refptr(new LayerWithForcedDrawsContent());
      scoped_refptr<LayerWithForcedDrawsContent> grandChildOfRS2 = make_scoped_refptr(new LayerWithForcedDrawsContent());
      parent->addChild(renderSurface1);
      parent->addChild(childOfRoot);
      renderSurface1->addChild(childOfRS1);
      renderSurface1->addChild(renderSurface2);
      renderSurface2->addChild(childOfRS2);
      childOfRoot->addChild(grandChildOfRoot);
      childOfRS1->addChild(grandChildOfRS1);
      childOfRS2->addChild(grandChildOfRS2);
  
      // Make our render surfaces.
      renderSurface1->setForceRenderSurface(true);
      renderSurface2->setForceRenderSurface(true);
  
      // Put an animated opacity on the render surface.
      addOpacityTransitionToController(*renderSurface1->layerAnimationController(), 10, 1, 0, false);
  
      // Also put an animated opacity on a layer without descendants.
      addOpacityTransitionToController(*grandChildOfRoot->layerAnimationController(), 10, 1, 0, false);
  
      WebTransformationMatrix layerTransform;
      layerTransform.translate(1, 1);
      WebTransformationMatrix sublayerTransform;
      sublayerTransform.scale3d(10, 1, 1);
  
      // Put a transform animation on the render surface.
      addAnimatedTransformToController(*renderSurface2->layerAnimationController(), 10, 30, 0);
  
      // Also put transform animations on grandChildOfRoot, and grandChildOfRS2
      addAnimatedTransformToController(*grandChildOfRoot->layerAnimationController(), 10, 30, 0);
      addAnimatedTransformToController(*grandChildOfRS2->layerAnimationController(), 10, 30, 0);
  
      setLayerPropertiesForTesting(parent.get(), layerTransform, sublayerTransform, gfx::PointF(0.25, 0), gfx::PointF(2.5, 0), gfx::Size(10, 10), false);
      setLayerPropertiesForTesting(renderSurface1.get(), layerTransform, sublayerTransform, gfx::PointF(0.25, 0), gfx::PointF(2.5, 0), gfx::Size(10, 10), false);
      setLayerPropertiesForTesting(renderSurface2.get(), layerTransform, sublayerTransform, gfx::PointF(0.25, 0), gfx::PointF(2.5, 0), gfx::Size(10, 10), false);
      setLayerPropertiesForTesting(childOfRoot.get(), layerTransform, sublayerTransform, gfx::PointF(0.25, 0), gfx::PointF(2.5, 0), gfx::Size(10, 10), false);
      setLayerPropertiesForTesting(childOfRS1.get(), layerTransform, sublayerTransform, gfx::PointF(0.25, 0), gfx::PointF(2.5, 0), gfx::Size(10, 10), false);
      setLayerPropertiesForTesting(childOfRS2.get(), layerTransform, sublayerTransform, gfx::PointF(0.25, 0), gfx::PointF(2.5, 0), gfx::Size(10, 10), false);
      setLayerPropertiesForTesting(grandChildOfRoot.get(), layerTransform, sublayerTransform, gfx::PointF(0.25, 0), gfx::PointF(2.5, 0), gfx::Size(10, 10), false);
      setLayerPropertiesForTesting(grandChildOfRS1.get(), layerTransform, sublayerTransform, gfx::PointF(0.25, 0), gfx::PointF(2.5, 0), gfx::Size(10, 10), false);
      setLayerPropertiesForTesting(grandChildOfRS2.get(), layerTransform, sublayerTransform, gfx::PointF(0.25, 0), gfx::PointF(2.5, 0), gfx::Size(10, 10), false);
  
      executeCalculateDrawTransformsAndVisibility(parent.get());
  
      // Only layers that are associated with render surfaces should have an actual renderSurface() value.
      //
      ASSERT_TRUE(parent->renderSurface());
      ASSERT_FALSE(childOfRoot->renderSurface());
      ASSERT_FALSE(grandChildOfRoot->renderSurface());
  
      ASSERT_TRUE(renderSurface1->renderSurface());
      ASSERT_FALSE(childOfRS1->renderSurface());
      ASSERT_FALSE(grandChildOfRS1->renderSurface());
  
      ASSERT_TRUE(renderSurface2->renderSurface());
      ASSERT_FALSE(childOfRS2->renderSurface());
      ASSERT_FALSE(grandChildOfRS2->renderSurface());
  
      // Verify all renderTarget accessors
      //
      EXPECT_EQ(parent, parent->renderTarget());
      EXPECT_EQ(parent, childOfRoot->renderTarget());
      EXPECT_EQ(parent, grandChildOfRoot->renderTarget());
  
      EXPECT_EQ(renderSurface1, renderSurface1->renderTarget());
      EXPECT_EQ(renderSurface1, childOfRS1->renderTarget());
      EXPECT_EQ(renderSurface1, grandChildOfRS1->renderTarget());
  
      EXPECT_EQ(renderSurface2, renderSurface2->renderTarget());
      EXPECT_EQ(renderSurface2, childOfRS2->renderTarget());
      EXPECT_EQ(renderSurface2, grandChildOfRS2->renderTarget());
  
      // Verify drawOpacityIsAnimating values
      //
      EXPECT_FALSE(parent->drawOpacityIsAnimating());
      EXPECT_FALSE(childOfRoot->drawOpacityIsAnimating());
      EXPECT_TRUE(grandChildOfRoot->drawOpacityIsAnimating());
      EXPECT_FALSE(renderSurface1->drawOpacityIsAnimating());
      EXPECT_TRUE(renderSurface1->renderSurface()->drawOpacityIsAnimating());
      EXPECT_FALSE(childOfRS1->drawOpacityIsAnimating());
      EXPECT_FALSE(grandChildOfRS1->drawOpacityIsAnimating());
      EXPECT_FALSE(renderSurface2->drawOpacityIsAnimating());
      EXPECT_FALSE(renderSurface2->renderSurface()->drawOpacityIsAnimating());
      EXPECT_FALSE(childOfRS2->drawOpacityIsAnimating());
      EXPECT_FALSE(grandChildOfRS2->drawOpacityIsAnimating());
  
      // Verify drawTransformsAnimatingInTarget values
      //
      EXPECT_FALSE(parent->drawTransformIsAnimating());
      EXPECT_FALSE(childOfRoot->drawTransformIsAnimating());
      EXPECT_TRUE(grandChildOfRoot->drawTransformIsAnimating());
      EXPECT_FALSE(renderSurface1->drawTransformIsAnimating());
      EXPECT_FALSE(renderSurface1->renderSurface()->targetSurfaceTransformsAreAnimating());
      EXPECT_FALSE(childOfRS1->drawTransformIsAnimating());
      EXPECT_FALSE(grandChildOfRS1->drawTransformIsAnimating());
      EXPECT_FALSE(renderSurface2->drawTransformIsAnimating());
      EXPECT_TRUE(renderSurface2->renderSurface()->targetSurfaceTransformsAreAnimating());
      EXPECT_FALSE(childOfRS2->drawTransformIsAnimating());
      EXPECT_TRUE(grandChildOfRS2->drawTransformIsAnimating());
  
      // Verify drawTransformsAnimatingInScreen values
      //
      EXPECT_FALSE(parent->screenSpaceTransformIsAnimating());
      EXPECT_FALSE(childOfRoot->screenSpaceTransformIsAnimating());
      EXPECT_TRUE(grandChildOfRoot->screenSpaceTransformIsAnimating());
      EXPECT_FALSE(renderSurface1->screenSpaceTransformIsAnimating());
      EXPECT_FALSE(renderSurface1->renderSurface()->screenSpaceTransformsAreAnimating());
      EXPECT_FALSE(childOfRS1->screenSpaceTransformIsAnimating());
      EXPECT_FALSE(grandChildOfRS1->screenSpaceTransformIsAnimating());
      EXPECT_TRUE(renderSurface2->screenSpaceTransformIsAnimating());
      EXPECT_TRUE(renderSurface2->renderSurface()->screenSpaceTransformsAreAnimating());
      EXPECT_TRUE(childOfRS2->screenSpaceTransformIsAnimating());
      EXPECT_TRUE(grandChildOfRS2->screenSpaceTransformIsAnimating());
  
  
      // Sanity check. If these fail there is probably a bug in the test itself.
      // It is expected that we correctly set up transforms so that the y-component of the screen-space transform
      // encodes the "depth" of the layer in the tree.
      EXPECT_FLOAT_EQ(1, parent->screenSpaceTransform().m42());
      EXPECT_FLOAT_EQ(2, childOfRoot->screenSpaceTransform().m42());
      EXPECT_FLOAT_EQ(3, grandChildOfRoot->screenSpaceTransform().m42());
  
      EXPECT_FLOAT_EQ(2, renderSurface1->screenSpaceTransform().m42());
      EXPECT_FLOAT_EQ(3, childOfRS1->screenSpaceTransform().m42());
      EXPECT_FLOAT_EQ(4, grandChildOfRS1->screenSpaceTransform().m42());
  
      EXPECT_FLOAT_EQ(3, renderSurface2->screenSpaceTransform().m42());
      EXPECT_FLOAT_EQ(4, childOfRS2->screenSpaceTransform().m42());
      EXPECT_FLOAT_EQ(5, grandChildOfRS2->screenSpaceTransform().m42());
  }
  
  TEST(LayerTreeHostCommonTest, verifyVisibleRectForIdentityTransform)
  {
      // Test the calculateVisibleRect() function works correctly for identity transforms.
  
      gfx::Rect targetSurfaceRect = gfx::Rect(gfx::Point(0, 0), gfx::Size(100, 100));
      WebTransformationMatrix layerToSurfaceTransform;
  
      // Case 1: Layer is contained within the surface.
      gfx::Rect layerContentRect = gfx::Rect(gfx::Point(10, 10), gfx::Size(30, 30));
      gfx::Rect expected = gfx::Rect(gfx::Point(10, 10), gfx::Size(30, 30));
      gfx::Rect actual = LayerTreeHostCommon::calculateVisibleRect(targetSurfaceRect, layerContentRect, layerToSurfaceTransform);
      EXPECT_RECT_EQ(expected, actual);
  
      // Case 2: Layer is outside the surface rect.
      layerContentRect = gfx::Rect(gfx::Point(120, 120), gfx::Size(30, 30));
      actual = LayerTreeHostCommon::calculateVisibleRect(targetSurfaceRect, layerContentRect, layerToSurfaceTransform);
      EXPECT_TRUE(actual.IsEmpty());
  
      // Case 3: Layer is partially overlapping the surface rect.
      layerContentRect = gfx::Rect(gfx::Point(80, 80), gfx::Size(30, 30));
      expected = gfx::Rect(gfx::Point(80, 80), gfx::Size(20, 20));
      actual = LayerTreeHostCommon::calculateVisibleRect(targetSurfaceRect, layerContentRect, layerToSurfaceTransform);
      EXPECT_RECT_EQ(expected, actual);
  }
  
  TEST(LayerTreeHostCommonTest, verifyVisibleRectForTranslations)
  {
      // Test the calculateVisibleRect() function works correctly for scaling transforms.
  
      gfx::Rect targetSurfaceRect = gfx::Rect(gfx::Point(0, 0), gfx::Size(100, 100));
      gfx::Rect layerContentRect = gfx::Rect(gfx::Point(0, 0), gfx::Size(30, 30));
      WebTransformationMatrix layerToSurfaceTransform;
  
      // Case 1: Layer is contained within the surface.
      layerToSurfaceTransform.makeIdentity();
      layerToSurfaceTransform.translate(10, 10);
      gfx::Rect expected = gfx::Rect(gfx::Point(0, 0), gfx::Size(30, 30));
      gfx::Rect actual = LayerTreeHostCommon::calculateVisibleRect(targetSurfaceRect, layerContentRect, layerToSurfaceTransform);
      EXPECT_RECT_EQ(expected, actual);
  
      // Case 2: Layer is outside the surface rect.
      layerToSurfaceTransform.makeIdentity();
      layerToSurfaceTransform.translate(120, 120);
      actual = LayerTreeHostCommon::calculateVisibleRect(targetSurfaceRect, layerContentRect, layerToSurfaceTransform);
      EXPECT_TRUE(actual.IsEmpty());
  
      // Case 3: Layer is partially overlapping the surface rect.
      layerToSurfaceTransform.makeIdentity();
      layerToSurfaceTransform.translate(80, 80);
      expected = gfx::Rect(gfx::Point(0, 0), gfx::Size(20, 20));
      actual = LayerTreeHostCommon::calculateVisibleRect(targetSurfaceRect, layerContentRect, layerToSurfaceTransform);
      EXPECT_RECT_EQ(expected, actual);
  }
  
  TEST(LayerTreeHostCommonTest, verifyVisibleRectFor2DRotations)
  {
      // Test the calculateVisibleRect() function works correctly for rotations about z-axis (i.e. 2D rotations).
      // Remember that calculateVisibleRect() should return the visible rect in the layer's space.
  
      gfx::Rect targetSurfaceRect = gfx::Rect(gfx::Point(0, 0), gfx::Size(100, 100));
      gfx::Rect layerContentRect = gfx::Rect(gfx::Point(0, 0), gfx::Size(30, 30));
      WebTransformationMatrix layerToSurfaceTransform;
  
      // Case 1: Layer is contained within the surface.
      layerToSurfaceTransform.makeIdentity();
      layerToSurfaceTransform.translate(50, 50);
      layerToSurfaceTransform.rotate(45);
      gfx::Rect expected = gfx::Rect(gfx::Point(0, 0), gfx::Size(30, 30));
      gfx::Rect actual = LayerTreeHostCommon::calculateVisibleRect(targetSurfaceRect, layerContentRect, layerToSurfaceTransform);
      EXPECT_RECT_EQ(expected, actual);
  
      // Case 2: Layer is outside the surface rect.
      layerToSurfaceTransform.makeIdentity();
      layerToSurfaceTransform.translate(-50, 0);
      layerToSurfaceTransform.rotate(45);
      actual = LayerTreeHostCommon::calculateVisibleRect(targetSurfaceRect, layerContentRect, layerToSurfaceTransform);
      EXPECT_TRUE(actual.IsEmpty());
  
      // Case 3: The layer is rotated about its top-left corner. In surface space, the layer
      //         is oriented diagonally, with the left half outside of the renderSurface. In
      //         this case, the visible rect should still be the entire layer (remember the
      //         visible rect is computed in layer space); both the top-left and
      //         bottom-right corners of the layer are still visible.
      layerToSurfaceTransform.makeIdentity();
      layerToSurfaceTransform.rotate(45);
      expected = gfx::Rect(gfx::Point(0, 0), gfx::Size(30, 30));
      actual = LayerTreeHostCommon::calculateVisibleRect(targetSurfaceRect, layerContentRect, layerToSurfaceTransform);
      EXPECT_RECT_EQ(expected, actual);
  
      // Case 4: The layer is rotated about its top-left corner, and translated upwards. In
      //         surface space, the layer is oriented diagonally, with only the top corner
      //         of the surface overlapping the layer. In layer space, the render surface
      //         overlaps the right side of the layer. The visible rect should be the
      //         layer's right half.
      layerToSurfaceTransform.makeIdentity();
      layerToSurfaceTransform.translate(0, -sqrt(2.0) * 15);
      layerToSurfaceTransform.rotate(45);
      expected = gfx::Rect(gfx::Point(15, 0), gfx::Size(15, 30)); // right half of layer bounds.
      actual = LayerTreeHostCommon::calculateVisibleRect(targetSurfaceRect, layerContentRect, layerToSurfaceTransform);
      EXPECT_RECT_EQ(expected, actual);
  }
  
  TEST(LayerTreeHostCommonTest, verifyVisibleRectFor3dOrthographicTransform)
  {
      // Test that the calculateVisibleRect() function works correctly for 3d transforms.
  
      gfx::Rect targetSurfaceRect = gfx::Rect(gfx::Point(0, 0), gfx::Size(100, 100));
      gfx::Rect layerContentRect = gfx::Rect(gfx::Point(0, 0), gfx::Size(100, 100));
      WebTransformationMatrix layerToSurfaceTransform;
  
      // Case 1: Orthographic projection of a layer rotated about y-axis by 45 degrees, should be fully contained in the renderSurface.
      layerToSurfaceTransform.makeIdentity();
      layerToSurfaceTransform.rotate3d(0, 45, 0);
      gfx::Rect expected = gfx::Rect(gfx::Point(0, 0), gfx::Size(100, 100));
      gfx::Rect actual = LayerTreeHostCommon::calculateVisibleRect(targetSurfaceRect, layerContentRect, layerToSurfaceTransform);
      EXPECT_RECT_EQ(expected, actual);
  
      // Case 2: Orthographic projection of a layer rotated about y-axis by 45 degrees, but
      //         shifted to the side so only the right-half the layer would be visible on
      //         the surface.
      double halfWidthOfRotatedLayer = (100 / sqrt(2.0)) * 0.5; // 100 is the un-rotated layer width; divided by sqrt(2) is the rotated width.
      layerToSurfaceTransform.makeIdentity();
      layerToSurfaceTransform.translate(-halfWidthOfRotatedLayer, 0);
      layerToSurfaceTransform.rotate3d(0, 45, 0); // rotates about the left edge of the layer
      expected = gfx::Rect(gfx::Point(50, 0), gfx::Size(50, 100)); // right half of the layer.
      actual = LayerTreeHostCommon::calculateVisibleRect(targetSurfaceRect, layerContentRect, layerToSurfaceTransform);
      EXPECT_RECT_EQ(expected, actual);
  }
  
  TEST(LayerTreeHostCommonTest, verifyVisibleRectFor3dPerspectiveTransform)
  {
      // Test the calculateVisibleRect() function works correctly when the layer has a
      // perspective projection onto the target surface.
  
      gfx::Rect targetSurfaceRect = gfx::Rect(gfx::Point(0, 0), gfx::Size(100, 100));
      gfx::Rect layerContentRect = gfx::Rect(gfx::Point(-50, -50), gfx::Size(200, 200));
      WebTransformationMatrix layerToSurfaceTransform;
  
      // Case 1: Even though the layer is twice as large as the surface, due to perspective
      //         foreshortening, the layer will fit fully in the surface when its translated
      //         more than the perspective amount.
      layerToSurfaceTransform.makeIdentity();
  
      // The following sequence of transforms applies the perspective about the center of the surface.
      layerToSurfaceTransform.translate(50, 50);
      layerToSurfaceTransform.applyPerspective(9);
      layerToSurfaceTransform.translate(-50, -50);
  
      // This translate places the layer in front of the surface's projection plane.
      layerToSurfaceTransform.translate3d(0, 0, -27);
  
      gfx::Rect expected = gfx::Rect(gfx::Point(-50, -50), gfx::Size(200, 200));
      gfx::Rect actual = LayerTreeHostCommon::calculateVisibleRect(targetSurfaceRect, layerContentRect, layerToSurfaceTransform);
      EXPECT_RECT_EQ(expected, actual);
  
      // Case 2: same projection as before, except that the layer is also translated to the
      //         side, so that only the right half of the layer should be visible.
      //
      // Explanation of expected result:
      // The perspective ratio is (z distance between layer and camera origin) / (z distance between projection plane and camera origin) == ((-27 - 9) / 9)
      // Then, by similar triangles, if we want to move a layer by translating -50 units in projected surface units (so that only half of it is
      // visible), then we would need to translate by (-36 / 9) * -50 == -200 in the layer's units.
      //
      layerToSurfaceTransform.translate3d(-200, 0, 0);
      expected = gfx::Rect(gfx::Point(50, -50), gfx::Size(100, 200)); // The right half of the layer's bounding rect.
      actual = LayerTreeHostCommon::calculateVisibleRect(targetSurfaceRect, layerContentRect, layerToSurfaceTransform);
      EXPECT_RECT_EQ(expected, actual);
  }
  
  TEST(LayerTreeHostCommonTest, verifyVisibleRectFor3dOrthographicIsNotClippedBehindSurface)
  {
      // There is currently no explicit concept of an orthographic projection plane in our
      // code (nor in the CSS spec to my knowledge). Therefore, layers that are technically
      // behind the surface in an orthographic world should not be clipped when they are
      // flattened to the surface.
  
      gfx::Rect targetSurfaceRect = gfx::Rect(gfx::Point(0, 0), gfx::Size(100, 100));
      gfx::Rect layerContentRect = gfx::Rect(gfx::Point(0, 0), gfx::Size(100, 100));
      WebTransformationMatrix layerToSurfaceTransform;
  
      // This sequence of transforms effectively rotates the layer about the y-axis at the
      // center of the layer.
      layerToSurfaceTransform.makeIdentity();
      layerToSurfaceTransform.translate(50, 0);
      layerToSurfaceTransform.rotate3d(0, 45, 0);
      layerToSurfaceTransform.translate(-50, 0);
  
      gfx::Rect expected = gfx::Rect(gfx::Point(0, 0), gfx::Size(100, 100));
      gfx::Rect actual = LayerTreeHostCommon::calculateVisibleRect(targetSurfaceRect, layerContentRect, layerToSurfaceTransform);
      EXPECT_RECT_EQ(expected, actual);
  }
  
  TEST(LayerTreeHostCommonTest, verifyVisibleRectFor3dPerspectiveWhenClippedByW)
  {
      // Test the calculateVisibleRect() function works correctly when projecting a surface
      // onto a layer, but the layer is partially behind the camera (not just behind the
      // projection plane). In this case, the cartesian coordinates may seem to be valid,
      // but actually they are not. The visibleRect needs to be properly clipped by the
      // w = 0 plane in homogeneous coordinates before converting to cartesian coordinates.
  
      gfx::Rect targetSurfaceRect = gfx::Rect(gfx::Point(-50, -50), gfx::Size(100, 100));
      gfx::Rect layerContentRect = gfx::Rect(gfx::Point(-10, -1), gfx::Size(20, 2));
      WebTransformationMatrix layerToSurfaceTransform;
  
      // The layer is positioned so that the right half of the layer should be in front of
      // the camera, while the other half is behind the surface's projection plane. The
      // following sequence of transforms applies the perspective and rotation about the
      // center of the layer.
      layerToSurfaceTransform.makeIdentity();
      layerToSurfaceTransform.applyPerspective(1);
      layerToSurfaceTransform.translate3d(-2, 0, 1);
      layerToSurfaceTransform.rotate3d(0, 45, 0);
  
      // Sanity check that this transform does indeed cause w < 0 when applying the
      // transform, otherwise this code is not testing the intended scenario.
      bool clipped = false;
      MathUtil::mapQuad(layerToSurfaceTransform, FloatQuad(gfx::RectF(layerContentRect)), clipped);
      ASSERT_TRUE(clipped);
  
      int expectedXPosition = 0;
      int expectedWidth = 10;
      gfx::Rect actual = LayerTreeHostCommon::calculateVisibleRect(targetSurfaceRect, layerContentRect, layerToSurfaceTransform);
      EXPECT_EQ(expectedXPosition, actual.x());
      EXPECT_EQ(expectedWidth, actual.width());
  }
  
  TEST(LayerTreeHostCommonTest, verifyVisibleRectForPerspectiveUnprojection)
  {
      // To determine visibleRect in layer space, there needs to be an un-projection from
      // surface space to layer space. When the original transform was a perspective
      // projection that was clipped, it returns a rect that encloses the clipped bounds.
      // Un-projecting this new rect may require clipping again.
  
      // This sequence of transforms causes one corner of the layer to protrude across the w = 0 plane, and should be clipped.
      gfx::Rect targetSurfaceRect = gfx::Rect(gfx::Point(-50, -50), gfx::Size(100, 100));
      gfx::Rect layerContentRect = gfx::Rect(gfx::Point(-10, -10), gfx::Size(20, 20));
      WebTransformationMatrix layerToSurfaceTransform;
      layerToSurfaceTransform.makeIdentity();
      layerToSurfaceTransform.applyPerspective(1);
      layerToSurfaceTransform.translate3d(0, 0, -5);
      layerToSurfaceTransform.rotate3d(0, 45, 0);
      layerToSurfaceTransform.rotate3d(80, 0, 0);
  
      // Sanity check that un-projection does indeed cause w < 0, otherwise this code is not
      // testing the intended scenario.
      bool clipped = false;
      gfx::RectF clippedRect = MathUtil::mapClippedRect(layerToSurfaceTransform, layerContentRect);
      MathUtil::projectQuad(layerToSurfaceTransform.inverse(), FloatQuad(clippedRect), clipped);
      ASSERT_TRUE(clipped);
  
      // Only the corner of the layer is not visible on the surface because of being
      // clipped. But, the net result of rounding visible region to an axis-aligned rect is
      // that the entire layer should still be considered visible.
      gfx::Rect expected = gfx::Rect(gfx::Point(-10, -10), gfx::Size(20, 20));
      gfx::Rect actual = LayerTreeHostCommon::calculateVisibleRect(targetSurfaceRect, layerContentRect, layerToSurfaceTransform);
      EXPECT_RECT_EQ(expected, actual);
  }
  
  TEST(LayerTreeHostCommonTest, verifyDrawableAndVisibleContentRectsForSimpleLayers)
  {
      scoped_refptr<Layer> root = Layer::create();
      scoped_refptr<LayerWithForcedDrawsContent> child1 = make_scoped_refptr(new LayerWithForcedDrawsContent());
      scoped_refptr<LayerWithForcedDrawsContent> child2 = make_scoped_refptr(new LayerWithForcedDrawsContent());
      scoped_refptr<LayerWithForcedDrawsContent> child3 = make_scoped_refptr(new LayerWithForcedDrawsContent());
      root->addChild(child1);
      root->addChild(child2);
      root->addChild(child3);
  
      WebTransformationMatrix identityMatrix;
      setLayerPropertiesForTesting(root.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(100, 100), false);
      setLayerPropertiesForTesting(child1.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(50, 50), false);
      setLayerPropertiesForTesting(child2.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(75, 75), gfx::Size(50, 50), false);
      setLayerPropertiesForTesting(child3.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(125, 125), gfx::Size(50, 50), false);
  
      executeCalculateDrawTransformsAndVisibility(root.get());
  
      EXPECT_RECT_EQ(gfx::Rect(0, 0, 100, 100), root->renderSurface()->drawableContentRect());
      EXPECT_RECT_EQ(gfx::Rect(0, 0, 100, 100), root->drawableContentRect());
  
      // Layers that do not draw content should have empty visibleContentRects.
      EXPECT_RECT_EQ(gfx::Rect(0, 0, 0, 0), root->visibleContentRect());
  
      // layer visibleContentRects are clipped by their targetSurface
      EXPECT_RECT_EQ(gfx::Rect(0, 0, 50, 50), child1->visibleContentRect());
      EXPECT_RECT_EQ(gfx::Rect(0, 0, 25, 25), child2->visibleContentRect());
      EXPECT_TRUE(child3->visibleContentRect().IsEmpty());
  
      // layer drawableContentRects are not clipped.
      EXPECT_RECT_EQ(gfx::Rect(0, 0, 50, 50), child1->drawableContentRect());
      EXPECT_RECT_EQ(gfx::Rect(75, 75, 50, 50), child2->drawableContentRect());
      EXPECT_RECT_EQ(gfx::Rect(125, 125, 50, 50), child3->drawableContentRect());
  }
  
  TEST(LayerTreeHostCommonTest, verifyDrawableAndVisibleContentRectsForLayersClippedByLayer)
  {
      scoped_refptr<Layer> root = Layer::create();
      scoped_refptr<Layer> child = Layer::create();
      scoped_refptr<LayerWithForcedDrawsContent> grandChild1 = make_scoped_refptr(new LayerWithForcedDrawsContent());
      scoped_refptr<LayerWithForcedDrawsContent> grandChild2 = make_scoped_refptr(new LayerWithForcedDrawsContent());
      scoped_refptr<LayerWithForcedDrawsContent> grandChild3 = make_scoped_refptr(new LayerWithForcedDrawsContent());
      root->addChild(child);
      child->addChild(grandChild1);
      child->addChild(grandChild2);
      child->addChild(grandChild3);
  
      WebTransformationMatrix identityMatrix;
      setLayerPropertiesForTesting(root.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(100, 100), false);
      setLayerPropertiesForTesting(child.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(100, 100), false);
      setLayerPropertiesForTesting(grandChild1.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(5, 5), gfx::Size(50, 50), false);
      setLayerPropertiesForTesting(grandChild2.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(75, 75), gfx::Size(50, 50), false);
      setLayerPropertiesForTesting(grandChild3.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(125, 125), gfx::Size(50, 50), false);
  
      child->setMasksToBounds(true);
      executeCalculateDrawTransformsAndVisibility(root.get());
  
      ASSERT_FALSE(child->renderSurface());
  
      EXPECT_RECT_EQ(gfx::Rect(0, 0, 100, 100), root->renderSurface()->drawableContentRect());
      EXPECT_RECT_EQ(gfx::Rect(0, 0, 100, 100), root->drawableContentRect());
  
      // Layers that do not draw content should have empty visibleContentRects.
      EXPECT_RECT_EQ(gfx::Rect(0, 0, 0, 0), root->visibleContentRect());
      EXPECT_RECT_EQ(gfx::Rect(0, 0, 0, 0), child->visibleContentRect());
  
      // All grandchild visibleContentRects should be clipped by child.
      EXPECT_RECT_EQ(gfx::Rect(0, 0, 50, 50), grandChild1->visibleContentRect());
      EXPECT_RECT_EQ(gfx::Rect(0, 0, 25, 25), grandChild2->visibleContentRect());
      EXPECT_TRUE(grandChild3->visibleContentRect().IsEmpty());
  
      // All grandchild drawableContentRects should also be clipped by child.
      EXPECT_RECT_EQ(gfx::Rect(5, 5, 50, 50), grandChild1->drawableContentRect());
      EXPECT_RECT_EQ(gfx::Rect(75, 75, 25, 25), grandChild2->drawableContentRect());
      EXPECT_TRUE(grandChild3->drawableContentRect().IsEmpty());
  }
  
  TEST(LayerTreeHostCommonTest, verifyDrawableAndVisibleContentRectsForLayersInUnclippedRenderSurface)
  {
      scoped_refptr<Layer> root = Layer::create();
      scoped_refptr<Layer> renderSurface1 = Layer::create();
      scoped_refptr<LayerWithForcedDrawsContent> child1 = make_scoped_refptr(new LayerWithForcedDrawsContent());
      scoped_refptr<LayerWithForcedDrawsContent> child2 = make_scoped_refptr(new LayerWithForcedDrawsContent());
      scoped_refptr<LayerWithForcedDrawsContent> child3 = make_scoped_refptr(new LayerWithForcedDrawsContent());
      root->addChild(renderSurface1);
      renderSurface1->addChild(child1);
      renderSurface1->addChild(child2);
      renderSurface1->addChild(child3);
  
      WebTransformationMatrix identityMatrix;
      setLayerPropertiesForTesting(root.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(100, 100), false);
      setLayerPropertiesForTesting(renderSurface1.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(3, 4), false);
      setLayerPropertiesForTesting(child1.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(5, 5), gfx::Size(50, 50), false);
      setLayerPropertiesForTesting(child2.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(75, 75), gfx::Size(50, 50), false);
      setLayerPropertiesForTesting(child3.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(125, 125), gfx::Size(50, 50), false);
  
      renderSurface1->setForceRenderSurface(true);
      executeCalculateDrawTransformsAndVisibility(root.get());
  
      ASSERT_TRUE(renderSurface1->renderSurface());
  
      EXPECT_RECT_EQ(gfx::Rect(0, 0, 100, 100), root->renderSurface()->drawableContentRect());
      EXPECT_RECT_EQ(gfx::Rect(0, 0, 100, 100), root->drawableContentRect());
  
      // Layers that do not draw content should have empty visibleContentRects.
      EXPECT_RECT_EQ(gfx::Rect(0, 0, 0, 0), root->visibleContentRect());
      EXPECT_RECT_EQ(gfx::Rect(0, 0, 0, 0), renderSurface1->visibleContentRect());
  
      // An unclipped surface grows its drawableContentRect to include all drawable regions of the subtree.
      EXPECT_RECT_EQ(gfx::Rect(5, 5, 170, 170), renderSurface1->renderSurface()->drawableContentRect());
  
      // All layers that draw content into the unclipped surface are also unclipped.
      EXPECT_RECT_EQ(gfx::Rect(0, 0, 50, 50), child1->visibleContentRect());
      EXPECT_RECT_EQ(gfx::Rect(0, 0, 50, 50), child2->visibleContentRect());
      EXPECT_RECT_EQ(gfx::Rect(0, 0, 50, 50), child3->visibleContentRect());
  
      EXPECT_RECT_EQ(gfx::Rect(5, 5, 50, 50), child1->drawableContentRect());
      EXPECT_RECT_EQ(gfx::Rect(75, 75, 50, 50), child2->drawableContentRect());
      EXPECT_RECT_EQ(gfx::Rect(125, 125, 50, 50), child3->drawableContentRect());
  }
  
  TEST(LayerTreeHostCommonTest, verifyDrawableAndVisibleContentRectsForLayersInClippedRenderSurface)
  {
      scoped_refptr<Layer> root = Layer::create();
      scoped_refptr<Layer> renderSurface1 = Layer::create();
      scoped_refptr<LayerWithForcedDrawsContent> child1 = make_scoped_refptr(new LayerWithForcedDrawsContent());
      scoped_refptr<LayerWithForcedDrawsContent> child2 = make_scoped_refptr(new LayerWithForcedDrawsContent());
      scoped_refptr<LayerWithForcedDrawsContent> child3 = make_scoped_refptr(new LayerWithForcedDrawsContent());
      root->addChild(renderSurface1);
      renderSurface1->addChild(child1);
      renderSurface1->addChild(child2);
      renderSurface1->addChild(child3);
  
      WebTransformationMatrix identityMatrix;
      setLayerPropertiesForTesting(root.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(100, 100), false);
      setLayerPropertiesForTesting(renderSurface1.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(3, 4), false);
      setLayerPropertiesForTesting(child1.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(5, 5), gfx::Size(50, 50), false);
      setLayerPropertiesForTesting(child2.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(75, 75), gfx::Size(50, 50), false);
      setLayerPropertiesForTesting(child3.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(125, 125), gfx::Size(50, 50), false);
  
      root->setMasksToBounds(true);
      renderSurface1->setForceRenderSurface(true);
      executeCalculateDrawTransformsAndVisibility(root.get());
  
      ASSERT_TRUE(renderSurface1->renderSurface());
  
      EXPECT_RECT_EQ(gfx::Rect(0, 0, 100, 100), root->renderSurface()->drawableContentRect());
      EXPECT_RECT_EQ(gfx::Rect(0, 0, 100, 100), root->drawableContentRect());
  
      // Layers that do not draw content should have empty visibleContentRects.
      EXPECT_RECT_EQ(gfx::Rect(0, 0, 0, 0), root->visibleContentRect());
      EXPECT_RECT_EQ(gfx::Rect(0, 0, 0, 0), renderSurface1->visibleContentRect());
  
      // A clipped surface grows its drawableContentRect to include all drawable regions of the subtree,
      // but also gets clamped by the ancestor's clip.
      EXPECT_RECT_EQ(gfx::Rect(5, 5, 95, 95), renderSurface1->renderSurface()->drawableContentRect());
  
      // All layers that draw content into the surface have their visibleContentRect clipped by the surface clipRect.
      EXPECT_RECT_EQ(gfx::Rect(0, 0, 50, 50), child1->visibleContentRect());
      EXPECT_RECT_EQ(gfx::Rect(0, 0, 25, 25), child2->visibleContentRect());
      EXPECT_TRUE(child3->visibleContentRect().IsEmpty());
  
      // But the drawableContentRects are unclipped.
      EXPECT_RECT_EQ(gfx::Rect(5, 5, 50, 50), child1->drawableContentRect());
      EXPECT_RECT_EQ(gfx::Rect(75, 75, 50, 50), child2->drawableContentRect());
      EXPECT_RECT_EQ(gfx::Rect(125, 125, 50, 50), child3->drawableContentRect());
  }
  
  TEST(LayerTreeHostCommonTest, verifyDrawableAndVisibleContentRectsForSurfaceHierarchy)
  {
      // Check that clipping does not propagate down surfaces.
      scoped_refptr<Layer> root = Layer::create();
      scoped_refptr<Layer> renderSurface1 = Layer::create();
      scoped_refptr<Layer> renderSurface2 = Layer::create();
      scoped_refptr<LayerWithForcedDrawsContent> child1 = make_scoped_refptr(new LayerWithForcedDrawsContent());
      scoped_refptr<LayerWithForcedDrawsContent> child2 = make_scoped_refptr(new LayerWithForcedDrawsContent());
      scoped_refptr<LayerWithForcedDrawsContent> child3 = make_scoped_refptr(new LayerWithForcedDrawsContent());
      root->addChild(renderSurface1);
      renderSurface1->addChild(renderSurface2);
      renderSurface2->addChild(child1);
      renderSurface2->addChild(child2);
      renderSurface2->addChild(child3);
  
      WebTransformationMatrix identityMatrix;
      setLayerPropertiesForTesting(root.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(100, 100), false);
      setLayerPropertiesForTesting(renderSurface1.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(3, 4), false);
      setLayerPropertiesForTesting(renderSurface2.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(7, 13), false);
      setLayerPropertiesForTesting(child1.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(5, 5), gfx::Size(50, 50), false);
      setLayerPropertiesForTesting(child2.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(75, 75), gfx::Size(50, 50), false);
      setLayerPropertiesForTesting(child3.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(125, 125), gfx::Size(50, 50), false);
  
      root->setMasksToBounds(true);
      renderSurface1->setForceRenderSurface(true);
      renderSurface2->setForceRenderSurface(true);
      executeCalculateDrawTransformsAndVisibility(root.get());
  
      ASSERT_TRUE(renderSurface1->renderSurface());
      ASSERT_TRUE(renderSurface2->renderSurface());
  
      EXPECT_RECT_EQ(gfx::Rect(0, 0, 100, 100), root->renderSurface()->drawableContentRect());
      EXPECT_RECT_EQ(gfx::Rect(0, 0, 100, 100), root->drawableContentRect());
  
      // Layers that do not draw content should have empty visibleContentRects.
      EXPECT_RECT_EQ(gfx::Rect(0, 0, 0, 0), root->visibleContentRect());
      EXPECT_RECT_EQ(gfx::Rect(0, 0, 0, 0), renderSurface1->visibleContentRect());
      EXPECT_RECT_EQ(gfx::Rect(0, 0, 0, 0), renderSurface2->visibleContentRect());
  
      // A clipped surface grows its drawableContentRect to include all drawable regions of the subtree,
      // but also gets clamped by the ancestor's clip.
      EXPECT_RECT_EQ(gfx::Rect(5, 5, 95, 95), renderSurface1->renderSurface()->drawableContentRect());
  
      // renderSurface1 lives in the "unclipped universe" of renderSurface1, and is only
      // implicitly clipped by renderSurface1's contentRect. So, renderSurface2 grows to
      // enclose all drawable content of its subtree.
      EXPECT_RECT_EQ(gfx::Rect(5, 5, 170, 170), renderSurface2->renderSurface()->drawableContentRect());
  
      // All layers that draw content into renderSurface2 think they are unclipped.
      EXPECT_RECT_EQ(gfx::Rect(0, 0, 50, 50), child1->visibleContentRect());
      EXPECT_RECT_EQ(gfx::Rect(0, 0, 50, 50), child2->visibleContentRect());
      EXPECT_RECT_EQ(gfx::Rect(0, 0, 50, 50), child3->visibleContentRect());
  
      // drawableContentRects are also unclipped.
      EXPECT_RECT_EQ(gfx::Rect(5, 5, 50, 50), child1->drawableContentRect());
      EXPECT_RECT_EQ(gfx::Rect(75, 75, 50, 50), child2->drawableContentRect());
      EXPECT_RECT_EQ(gfx::Rect(125, 125, 50, 50), child3->drawableContentRect());
  }
  
  TEST(LayerTreeHostCommonTest, verifyDrawableAndVisibleContentRectsWithTransformOnUnclippedSurface)
  {
      // Layers that have non-axis aligned bounds (due to transforms) have an expanded,
      // axis-aligned drawableContentRect and visibleContentRect.
  
      scoped_refptr<Layer> root = Layer::create();
      scoped_refptr<Layer> renderSurface1 = Layer::create();
      scoped_refptr<LayerWithForcedDrawsContent> child1 = make_scoped_refptr(new LayerWithForcedDrawsContent());
      root->addChild(renderSurface1);
      renderSurface1->addChild(child1);
  
      WebTransformationMatrix identityMatrix;
      WebTransformationMatrix childRotation;
      childRotation.rotate(45);
      setLayerPropertiesForTesting(root.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(100, 100), false);
      setLayerPropertiesForTesting(renderSurface1.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(3, 4), false);
      setLayerPropertiesForTesting(child1.get(), childRotation, identityMatrix, gfx::PointF(0.5, 0.5), gfx::PointF(25, 25), gfx::Size(50, 50), false);
  
      renderSurface1->setForceRenderSurface(true);
      executeCalculateDrawTransformsAndVisibility(root.get());
  
      ASSERT_TRUE(renderSurface1->renderSurface());
  
      EXPECT_RECT_EQ(gfx::Rect(0, 0, 100, 100), root->renderSurface()->drawableContentRect());
      EXPECT_RECT_EQ(gfx::Rect(0, 0, 100, 100), root->drawableContentRect());
  
      // Layers that do not draw content should have empty visibleContentRects.
      EXPECT_RECT_EQ(gfx::Rect(0, 0, 0, 0), root->visibleContentRect());
      EXPECT_RECT_EQ(gfx::Rect(0, 0, 0, 0), renderSurface1->visibleContentRect());
  
      // The unclipped surface grows its drawableContentRect to include all drawable regions of the subtree.
      int diagonalRadius = ceil(sqrt(2.0) * 25);
      gfx::Rect expectedSurfaceDrawableContent = gfx::Rect(50 - diagonalRadius, 50 - diagonalRadius, diagonalRadius * 2, diagonalRadius * 2);
      EXPECT_RECT_EQ(expectedSurfaceDrawableContent, renderSurface1->renderSurface()->drawableContentRect());
  
      // All layers that draw content into the unclipped surface are also unclipped.
      EXPECT_RECT_EQ(gfx::Rect(0, 0, 50, 50), child1->visibleContentRect());
      EXPECT_RECT_EQ(expectedSurfaceDrawableContent, child1->drawableContentRect());
  }
  
  TEST(LayerTreeHostCommonTest, verifyDrawableAndVisibleContentRectsWithTransformOnClippedSurface)
  {
      // Layers that have non-axis aligned bounds (due to transforms) have an expanded,
      // axis-aligned drawableContentRect and visibleContentRect.
  
      scoped_refptr<Layer> root = Layer::create();
      scoped_refptr<Layer> renderSurface1 = Layer::create();
      scoped_refptr<LayerWithForcedDrawsContent> child1 = make_scoped_refptr(new LayerWithForcedDrawsContent());
      root->addChild(renderSurface1);
      renderSurface1->addChild(child1);
  
      WebTransformationMatrix identityMatrix;
      WebTransformationMatrix childRotation;
      childRotation.rotate(45);
      setLayerPropertiesForTesting(root.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(50, 50), false);
      setLayerPropertiesForTesting(renderSurface1.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(3, 4), false);
      setLayerPropertiesForTesting(child1.get(), childRotation, identityMatrix, gfx::PointF(0.5, 0.5), gfx::PointF(25, 25), gfx::Size(50, 50), false);
  
      root->setMasksToBounds(true);
      renderSurface1->setForceRenderSurface(true);
      executeCalculateDrawTransformsAndVisibility(root.get());
  
      ASSERT_TRUE(renderSurface1->renderSurface());
  
      // The clipped surface clamps the drawableContentRect that encloses the rotated layer.
      int diagonalRadius = ceil(sqrt(2.0) * 25);
      gfx::Rect unclippedSurfaceContent = gfx::Rect(50 - diagonalRadius, 50 - diagonalRadius, diagonalRadius * 2, diagonalRadius * 2);
      gfx::Rect expectedSurfaceDrawableContent = gfx::IntersectRects(unclippedSurfaceContent, gfx::Rect(0, 0, 50, 50));
      EXPECT_RECT_EQ(expectedSurfaceDrawableContent, renderSurface1->renderSurface()->drawableContentRect());
  
      // On the clipped surface, only a quarter  of the child1 is visible, but when rotating
      // it back to  child1's content space, the actual enclosing rect ends up covering the
      // full left half of child1.
      EXPECT_RECT_EQ(gfx::Rect(0, 0, 26, 50), child1->visibleContentRect());
  
      // The child's drawableContentRect is unclipped.
      EXPECT_RECT_EQ(unclippedSurfaceContent, child1->drawableContentRect());
  }
  
  TEST(LayerTreeHostCommonTest, verifyDrawableAndVisibleContentRectsInHighDPI)
  {
      MockContentLayerClient client;
  
      scoped_refptr<Layer> root = Layer::create();
      scoped_refptr<ContentLayer> renderSurface1 = createDrawableContentLayer(&client);
      scoped_refptr<ContentLayer> renderSurface2 = createDrawableContentLayer(&client);
      scoped_refptr<ContentLayer> child1 = createDrawableContentLayer(&client);
      scoped_refptr<ContentLayer> child2 = createDrawableContentLayer(&client);
      scoped_refptr<ContentLayer> child3 = createDrawableContentLayer(&client);
      root->addChild(renderSurface1);
      renderSurface1->addChild(renderSurface2);
      renderSurface2->addChild(child1);
      renderSurface2->addChild(child2);
      renderSurface2->addChild(child3);
  
      WebTransformationMatrix identityMatrix;
      setLayerPropertiesForTesting(root.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(100, 100), false);
      setLayerPropertiesForTesting(renderSurface1.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(5, 5), gfx::Size(3, 4), false);
      setLayerPropertiesForTesting(renderSurface2.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(5, 5), gfx::Size(7, 13), false);
      setLayerPropertiesForTesting(child1.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(5, 5), gfx::Size(50, 50), false);
      setLayerPropertiesForTesting(child2.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(75, 75), gfx::Size(50, 50), false);
      setLayerPropertiesForTesting(child3.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(125, 125), gfx::Size(50, 50), false);
  
      const double deviceScaleFactor = 2;
      root->setContentsScale(deviceScaleFactor);
      renderSurface1->setContentsScale(deviceScaleFactor);
      renderSurface2->setContentsScale(deviceScaleFactor);
      child1->setContentsScale(deviceScaleFactor);
      child2->setContentsScale(deviceScaleFactor);
      child3->setContentsScale(deviceScaleFactor);
  
      root->setMasksToBounds(true);
      renderSurface1->setForceRenderSurface(true);
      renderSurface2->setForceRenderSurface(true);
      executeCalculateDrawTransformsAndVisibility(root.get(), deviceScaleFactor);
  
      ASSERT_TRUE(renderSurface1->renderSurface());
      ASSERT_TRUE(renderSurface2->renderSurface());
  
      // DrawableContentRects for all layers and surfaces are scaled by deviceScaleFactor.
      EXPECT_RECT_EQ(gfx::Rect(0, 0, 200, 200), root->renderSurface()->drawableContentRect());
      EXPECT_RECT_EQ(gfx::Rect(0, 0, 200, 200), root->drawableContentRect());
      EXPECT_RECT_EQ(gfx::Rect(10, 10, 190, 190), renderSurface1->renderSurface()->drawableContentRect());
  
      // renderSurface2 lives in the "unclipped universe" of renderSurface1, and
      // is only implicitly clipped by renderSurface1.
      EXPECT_RECT_EQ(gfx::Rect(10, 10, 350, 350), renderSurface2->renderSurface()->drawableContentRect());
  
      EXPECT_RECT_EQ(gfx::Rect(10, 10, 100, 100), child1->drawableContentRect());
      EXPECT_RECT_EQ(gfx::Rect(150, 150, 100, 100), child2->drawableContentRect());
      EXPECT_RECT_EQ(gfx::Rect(250, 250, 100, 100), child3->drawableContentRect());
  
      // The root layer does not actually draw content of its own.
      EXPECT_RECT_EQ(gfx::Rect(0, 0, 0, 0), root->visibleContentRect());
  
      // All layer visibleContentRects are expressed in content space of each
      // layer, so they are also scaled by the deviceScaleFactor.
      EXPECT_RECT_EQ(gfx::Rect(0, 0, 6, 8), renderSurface1->visibleContentRect());
      EXPECT_RECT_EQ(gfx::Rect(0, 0, 14, 26), renderSurface2->visibleContentRect());
      EXPECT_RECT_EQ(gfx::Rect(0, 0, 100, 100), child1->visibleContentRect());
      EXPECT_RECT_EQ(gfx::Rect(0, 0, 100, 100), child2->visibleContentRect());
      EXPECT_RECT_EQ(gfx::Rect(0, 0, 100, 100), child3->visibleContentRect());
  }
  
  TEST(LayerTreeHostCommonTest, verifyBackFaceCullingWithoutPreserves3d)
  {
      // Verify the behavior of back-face culling when there are no preserve-3d layers. Note
      // that 3d transforms still apply in this case, but they are "flattened" to each
      // parent layer according to current W3C spec.
  
      const WebTransformationMatrix identityMatrix;
      scoped_refptr<Layer> parent = Layer::create();
      scoped_refptr<LayerWithForcedDrawsContent> frontFacingChild = make_scoped_refptr(new LayerWithForcedDrawsContent());
      scoped_refptr<LayerWithForcedDrawsContent> backFacingChild = make_scoped_refptr(new LayerWithForcedDrawsContent());
      scoped_refptr<LayerWithForcedDrawsContent> frontFacingSurface = make_scoped_refptr(new LayerWithForcedDrawsContent());
      scoped_refptr<LayerWithForcedDrawsContent> backFacingSurface = make_scoped_refptr(new LayerWithForcedDrawsContent());
      scoped_refptr<LayerWithForcedDrawsContent> frontFacingChildOfFrontFacingSurface = make_scoped_refptr(new LayerWithForcedDrawsContent());
      scoped_refptr<LayerWithForcedDrawsContent> backFacingChildOfFrontFacingSurface = make_scoped_refptr(new LayerWithForcedDrawsContent());
      scoped_refptr<LayerWithForcedDrawsContent> frontFacingChildOfBackFacingSurface = make_scoped_refptr(new LayerWithForcedDrawsContent());
      scoped_refptr<LayerWithForcedDrawsContent> backFacingChildOfBackFacingSurface = make_scoped_refptr(new LayerWithForcedDrawsContent());
  
      parent->addChild(frontFacingChild);
      parent->addChild(backFacingChild);
      parent->addChild(frontFacingSurface);
      parent->addChild(backFacingSurface);
      frontFacingSurface->addChild(frontFacingChildOfFrontFacingSurface);
      frontFacingSurface->addChild(backFacingChildOfFrontFacingSurface);
      backFacingSurface->addChild(frontFacingChildOfBackFacingSurface);
      backFacingSurface->addChild(backFacingChildOfBackFacingSurface);
  
      // Nothing is double-sided
      frontFacingChild->setDoubleSided(false);
      backFacingChild->setDoubleSided(false);
      frontFacingSurface->setDoubleSided(false);
      backFacingSurface->setDoubleSided(false);
      frontFacingChildOfFrontFacingSurface->setDoubleSided(false);
      backFacingChildOfFrontFacingSurface->setDoubleSided(false);
      frontFacingChildOfBackFacingSurface->setDoubleSided(false);
      backFacingChildOfBackFacingSurface->setDoubleSided(false);
  
      WebTransformationMatrix backfaceMatrix;
      backfaceMatrix.translate(50, 50);
      backfaceMatrix.rotate3d(0, 1, 0, 180);
      backfaceMatrix.translate(-50, -50);
  
      // Having a descendant and opacity will force these to have render surfaces.
      frontFacingSurface->setOpacity(0.5);
      backFacingSurface->setOpacity(0.5);
  
      // Nothing preserves 3d. According to current W3C CSS Transforms spec, these layers
      // should blindly use their own local transforms to determine back-face culling.
      setLayerPropertiesForTesting(parent.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(100, 100), false);
      setLayerPropertiesForTesting(frontFacingChild.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(100, 100), false);
      setLayerPropertiesForTesting(backFacingChild.get(), backfaceMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(100, 100), false);
      setLayerPropertiesForTesting(frontFacingSurface.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(100, 100), false);
      setLayerPropertiesForTesting(backFacingSurface.get(), backfaceMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(100, 100), false);
      setLayerPropertiesForTesting(frontFacingChildOfFrontFacingSurface.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(100, 100), false);
      setLayerPropertiesForTesting(backFacingChildOfFrontFacingSurface.get(), backfaceMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(100, 100), false);
      setLayerPropertiesForTesting(frontFacingChildOfBackFacingSurface.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(100, 100), false);
      setLayerPropertiesForTesting(backFacingChildOfBackFacingSurface.get(), backfaceMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(100, 100), false);
  
      std::vector<scoped_refptr<Layer> > renderSurfaceLayerList;
      int dummyMaxTextureSize = 512;
      LayerTreeHostCommon::calculateDrawTransforms(parent.get(), parent->bounds(), 1, 1, dummyMaxTextureSize, renderSurfaceLayerList);
  
      // Verify which renderSurfaces were created.
      EXPECT_FALSE(frontFacingChild->renderSurface());
      EXPECT_FALSE(backFacingChild->renderSurface());
      EXPECT_TRUE(frontFacingSurface->renderSurface());
      EXPECT_TRUE(backFacingSurface->renderSurface());
      EXPECT_FALSE(frontFacingChildOfFrontFacingSurface->renderSurface());
      EXPECT_FALSE(backFacingChildOfFrontFacingSurface->renderSurface());
      EXPECT_FALSE(frontFacingChildOfBackFacingSurface->renderSurface());
      EXPECT_FALSE(backFacingChildOfBackFacingSurface->renderSurface());
  
      // Verify the renderSurfaceLayerList.
      ASSERT_EQ(3u, renderSurfaceLayerList.size());
      EXPECT_EQ(parent->id(), renderSurfaceLayerList[0]->id());
      EXPECT_EQ(frontFacingSurface->id(), renderSurfaceLayerList[1]->id());
      // Even though the back facing surface LAYER gets culled, the other descendants should still be added, so the SURFACE should not be culled.
      EXPECT_EQ(backFacingSurface->id(), renderSurfaceLayerList[2]->id());
  
      // Verify root surface's layerList.
      ASSERT_EQ(3u, renderSurfaceLayerList[0]->renderSurface()->layerList().size());
      EXPECT_EQ(frontFacingChild->id(), renderSurfaceLayerList[0]->renderSurface()->layerList()[0]->id());
      EXPECT_EQ(frontFacingSurface->id(), renderSurfaceLayerList[0]->renderSurface()->layerList()[1]->id());
      EXPECT_EQ(backFacingSurface->id(), renderSurfaceLayerList[0]->renderSurface()->layerList()[2]->id());
  
      // Verify frontFacingSurface's layerList.
      ASSERT_EQ(2u, renderSurfaceLayerList[1]->renderSurface()->layerList().size());
      EXPECT_EQ(frontFacingSurface->id(), renderSurfaceLayerList[1]->renderSurface()->layerList()[0]->id());
      EXPECT_EQ(frontFacingChildOfFrontFacingSurface->id(), renderSurfaceLayerList[1]->renderSurface()->layerList()[1]->id());
  
      // Verify backFacingSurface's layerList; its own layer should be culled from the surface list.
      ASSERT_EQ(1u, renderSurfaceLayerList[2]->renderSurface()->layerList().size());
      EXPECT_EQ(frontFacingChildOfBackFacingSurface->id(), renderSurfaceLayerList[2]->renderSurface()->layerList()[0]->id());
  }
  
  TEST(LayerTreeHostCommonTest, verifyBackFaceCullingWithPreserves3d)
  {
      // Verify the behavior of back-face culling when preserves-3d transform style is used.
  
      const WebTransformationMatrix identityMatrix;
      scoped_refptr<Layer> parent = Layer::create();
      scoped_refptr<LayerWithForcedDrawsContent> frontFacingChild = make_scoped_refptr(new LayerWithForcedDrawsContent());
      scoped_refptr<LayerWithForcedDrawsContent> backFacingChild = make_scoped_refptr(new LayerWithForcedDrawsContent());
      scoped_refptr<LayerWithForcedDrawsContent> frontFacingSurface = make_scoped_refptr(new LayerWithForcedDrawsContent());
      scoped_refptr<LayerWithForcedDrawsContent> backFacingSurface = make_scoped_refptr(new LayerWithForcedDrawsContent());
      scoped_refptr<LayerWithForcedDrawsContent> frontFacingChildOfFrontFacingSurface = make_scoped_refptr(new LayerWithForcedDrawsContent());
      scoped_refptr<LayerWithForcedDrawsContent> backFacingChildOfFrontFacingSurface = make_scoped_refptr(new LayerWithForcedDrawsContent());
      scoped_refptr<LayerWithForcedDrawsContent> frontFacingChildOfBackFacingSurface = make_scoped_refptr(new LayerWithForcedDrawsContent());
      scoped_refptr<LayerWithForcedDrawsContent> backFacingChildOfBackFacingSurface = make_scoped_refptr(new LayerWithForcedDrawsContent());
      scoped_refptr<LayerWithForcedDrawsContent> dummyReplicaLayer1 = make_scoped_refptr(new LayerWithForcedDrawsContent());
      scoped_refptr<LayerWithForcedDrawsContent> dummyReplicaLayer2 = make_scoped_refptr(new LayerWithForcedDrawsContent());
  
      parent->addChild(frontFacingChild);
      parent->addChild(backFacingChild);
      parent->addChild(frontFacingSurface);
      parent->addChild(backFacingSurface);
      frontFacingSurface->addChild(frontFacingChildOfFrontFacingSurface);
      frontFacingSurface->addChild(backFacingChildOfFrontFacingSurface);
      backFacingSurface->addChild(frontFacingChildOfBackFacingSurface);
      backFacingSurface->addChild(backFacingChildOfBackFacingSurface);
  
      // Nothing is double-sided
      frontFacingChild->setDoubleSided(false);
      backFacingChild->setDoubleSided(false);
      frontFacingSurface->setDoubleSided(false);
      backFacingSurface->setDoubleSided(false);
      frontFacingChildOfFrontFacingSurface->setDoubleSided(false);
      backFacingChildOfFrontFacingSurface->setDoubleSided(false);
      frontFacingChildOfBackFacingSurface->setDoubleSided(false);
      backFacingChildOfBackFacingSurface->setDoubleSided(false);
  
      WebTransformationMatrix backfaceMatrix;
      backfaceMatrix.translate(50, 50);
      backfaceMatrix.rotate3d(0, 1, 0, 180);
      backfaceMatrix.translate(-50, -50);
  
      // Opacity will not force creation of renderSurfaces in this case because of the
      // preserve-3d transform style. Instead, an example of when a surface would be
      // created with preserve-3d is when there is a replica layer.
      frontFacingSurface->setReplicaLayer(dummyReplicaLayer1.get());
      backFacingSurface->setReplicaLayer(dummyReplicaLayer2.get());
  
      // Each surface creates its own new 3d rendering context (as defined by W3C spec).
      // According to current W3C CSS Transforms spec, layers in a 3d rendering context
      // should use the transform with respect to that context. This 3d rendering context
      // occurs when (a) parent's transform style is flat and (b) the layer's transform
      // style is preserve-3d.
      setLayerPropertiesForTesting(parent.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(100, 100), false); // parent transform style is flat.
      setLayerPropertiesForTesting(frontFacingChild.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(100, 100), false);
      setLayerPropertiesForTesting(backFacingChild.get(), backfaceMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(100, 100), false);
      setLayerPropertiesForTesting(frontFacingSurface.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(100, 100), true); // surface transform style is preserve-3d.
      setLayerPropertiesForTesting(backFacingSurface.get(), backfaceMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(100, 100), true); // surface transform style is preserve-3d.
      setLayerPropertiesForTesting(frontFacingChildOfFrontFacingSurface.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(100, 100), false);
      setLayerPropertiesForTesting(backFacingChildOfFrontFacingSurface.get(), backfaceMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(100, 100), false);
      setLayerPropertiesForTesting(frontFacingChildOfBackFacingSurface.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(100, 100), false);
      setLayerPropertiesForTesting(backFacingChildOfBackFacingSurface.get(), backfaceMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(100, 100), false);
  
      std::vector<scoped_refptr<Layer> > renderSurfaceLayerList;
      int dummyMaxTextureSize = 512;
      LayerTreeHostCommon::calculateDrawTransforms(parent.get(), parent->bounds(), 1, 1, dummyMaxTextureSize, renderSurfaceLayerList);
  
      // Verify which renderSurfaces were created.
      EXPECT_FALSE(frontFacingChild->renderSurface());
      EXPECT_FALSE(backFacingChild->renderSurface());
      EXPECT_TRUE(frontFacingSurface->renderSurface());
      EXPECT_FALSE(backFacingSurface->renderSurface());
      EXPECT_FALSE(frontFacingChildOfFrontFacingSurface->renderSurface());
      EXPECT_FALSE(backFacingChildOfFrontFacingSurface->renderSurface());
      EXPECT_FALSE(frontFacingChildOfBackFacingSurface->renderSurface());
      EXPECT_FALSE(backFacingChildOfBackFacingSurface->renderSurface());
  
      // Verify the renderSurfaceLayerList. The back-facing surface should be culled.
      ASSERT_EQ(2u, renderSurfaceLayerList.size());
      EXPECT_EQ(parent->id(), renderSurfaceLayerList[0]->id());
      EXPECT_EQ(frontFacingSurface->id(), renderSurfaceLayerList[1]->id());
  
      // Verify root surface's layerList.
      ASSERT_EQ(2u, renderSurfaceLayerList[0]->renderSurface()->layerList().size());
      EXPECT_EQ(frontFacingChild->id(), renderSurfaceLayerList[0]->renderSurface()->layerList()[0]->id());
      EXPECT_EQ(frontFacingSurface->id(), renderSurfaceLayerList[0]->renderSurface()->layerList()[1]->id());
  
      // Verify frontFacingSurface's layerList.
      ASSERT_EQ(2u, renderSurfaceLayerList[1]->renderSurface()->layerList().size());
      EXPECT_EQ(frontFacingSurface->id(), renderSurfaceLayerList[1]->renderSurface()->layerList()[0]->id());
      EXPECT_EQ(frontFacingChildOfFrontFacingSurface->id(), renderSurfaceLayerList[1]->renderSurface()->layerList()[1]->id());
  }
  
  TEST(LayerTreeHostCommonTest, verifyBackFaceCullingWithAnimatingTransforms)
  {
      // Verify that layers are appropriately culled when their back face is showing and
      // they are not double sided, while animations are going on.
      //
      // Layers that are animating do not get culled on the main thread, as their transforms should be
      // treated as "unknown" so we can not be sure that their back face is really showing.
      //
  
      const WebTransformationMatrix identityMatrix;
      scoped_refptr<Layer> parent = Layer::create();
      scoped_refptr<LayerWithForcedDrawsContent> child = make_scoped_refptr(new LayerWithForcedDrawsContent());
      scoped_refptr<LayerWithForcedDrawsContent> animatingSurface = make_scoped_refptr(new LayerWithForcedDrawsContent());
      scoped_refptr<LayerWithForcedDrawsContent> childOfAnimatingSurface = make_scoped_refptr(new LayerWithForcedDrawsContent());
      scoped_refptr<LayerWithForcedDrawsContent> animatingChild = make_scoped_refptr(new LayerWithForcedDrawsContent());
      scoped_refptr<LayerWithForcedDrawsContent> child2 = make_scoped_refptr(new LayerWithForcedDrawsContent());
  
      parent->addChild(child);
      parent->addChild(animatingSurface);
      animatingSurface->addChild(childOfAnimatingSurface);
      parent->addChild(animatingChild);
      parent->addChild(child2);
  
      // Nothing is double-sided
      child->setDoubleSided(false);
      child2->setDoubleSided(false);
      animatingSurface->setDoubleSided(false);
      childOfAnimatingSurface->setDoubleSided(false);
      animatingChild->setDoubleSided(false);
  
      WebTransformationMatrix backfaceMatrix;
      backfaceMatrix.translate(50, 50);
      backfaceMatrix.rotate3d(0, 1, 0, 180);
      backfaceMatrix.translate(-50, -50);
  
      // Make our render surface.
      animatingSurface->setForceRenderSurface(true);
  
      // Animate the transform on the render surface.
      addAnimatedTransformToController(*animatingSurface->layerAnimationController(), 10, 30, 0);
      // This is just an animating layer, not a surface.
      addAnimatedTransformToController(*animatingChild->layerAnimationController(), 10, 30, 0);
  
      setLayerPropertiesForTesting(parent.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(100, 100), false);
      setLayerPropertiesForTesting(child.get(), backfaceMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(100, 100), false);
      setLayerPropertiesForTesting(animatingSurface.get(), backfaceMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(100, 100), false);
      setLayerPropertiesForTesting(childOfAnimatingSurface.get(), backfaceMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(100, 100), false);
      setLayerPropertiesForTesting(animatingChild.get(), backfaceMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(100, 100), false);
      setLayerPropertiesForTesting(child2.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(100, 100), false);
  
      std::vector<scoped_refptr<Layer> > renderSurfaceLayerList;
      int dummyMaxTextureSize = 512;
      LayerTreeHostCommon::calculateDrawTransforms(parent.get(), parent->bounds(), 1, 1, dummyMaxTextureSize, renderSurfaceLayerList);
  
      EXPECT_FALSE(child->renderSurface());
      EXPECT_TRUE(animatingSurface->renderSurface());
      EXPECT_FALSE(childOfAnimatingSurface->renderSurface());
      EXPECT_FALSE(animatingChild->renderSurface());
      EXPECT_FALSE(child2->renderSurface());
  
      // Verify that the animatingChild and childOfAnimatingSurface were not culled, but that child was.
      ASSERT_EQ(2u, renderSurfaceLayerList.size());
      EXPECT_EQ(parent->id(), renderSurfaceLayerList[0]->id());
      EXPECT_EQ(animatingSurface->id(), renderSurfaceLayerList[1]->id());
  
      // The non-animating child be culled from the layer list for the parent render surface.
      ASSERT_EQ(3u, renderSurfaceLayerList[0]->renderSurface()->layerList().size());
      EXPECT_EQ(animatingSurface->id(), renderSurfaceLayerList[0]->renderSurface()->layerList()[0]->id());
      EXPECT_EQ(animatingChild->id(), renderSurfaceLayerList[0]->renderSurface()->layerList()[1]->id());
      EXPECT_EQ(child2->id(), renderSurfaceLayerList[0]->renderSurface()->layerList()[2]->id());
  
      ASSERT_EQ(2u, renderSurfaceLayerList[1]->renderSurface()->layerList().size());
      EXPECT_EQ(animatingSurface->id(), renderSurfaceLayerList[1]->renderSurface()->layerList()[0]->id());
      EXPECT_EQ(childOfAnimatingSurface->id(), renderSurfaceLayerList[1]->renderSurface()->layerList()[1]->id());
  
      EXPECT_FALSE(child2->visibleContentRect().IsEmpty());
  
      // The animating layers should have a visibleContentRect that represents the area of the front face that is within the viewport.
      EXPECT_EQ(animatingChild->visibleContentRect(), gfx::Rect(gfx::Point(), animatingChild->contentBounds()));
      EXPECT_EQ(animatingSurface->visibleContentRect(), gfx::Rect(gfx::Point(), animatingSurface->contentBounds()));
      // And layers in the subtree of the animating layer should have valid visibleContentRects also.
      EXPECT_EQ(childOfAnimatingSurface->visibleContentRect(), gfx::Rect(gfx::Point(), childOfAnimatingSurface->contentBounds()));
  }
  
  TEST(LayerTreeHostCommonTest, verifyBackFaceCullingWithPreserves3dForFlatteningSurface)
  {
      // Verify the behavior of back-face culling for a renderSurface that is created
      // when it flattens its subtree, and its parent has preserves-3d.
  
      const WebTransformationMatrix identityMatrix;
      scoped_refptr<Layer> parent = Layer::create();
      scoped_refptr<LayerWithForcedDrawsContent> frontFacingSurface = make_scoped_refptr(new LayerWithForcedDrawsContent());
      scoped_refptr<LayerWithForcedDrawsContent> backFacingSurface = make_scoped_refptr(new LayerWithForcedDrawsContent());
      scoped_refptr<LayerWithForcedDrawsContent> child1 = make_scoped_refptr(new LayerWithForcedDrawsContent());
      scoped_refptr<LayerWithForcedDrawsContent> child2 = make_scoped_refptr(new LayerWithForcedDrawsContent());
  
      parent->addChild(frontFacingSurface);
      parent->addChild(backFacingSurface);
      frontFacingSurface->addChild(child1);
      backFacingSurface->addChild(child2);
  
      // RenderSurfaces are not double-sided
      frontFacingSurface->setDoubleSided(false);
      backFacingSurface->setDoubleSided(false);
  
      WebTransformationMatrix backfaceMatrix;
      backfaceMatrix.translate(50, 50);
      backfaceMatrix.rotate3d(0, 1, 0, 180);
      backfaceMatrix.translate(-50, -50);
  
      setLayerPropertiesForTesting(parent.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(100, 100), true); // parent transform style is preserve3d.
      setLayerPropertiesForTesting(frontFacingSurface.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(100, 100), false); // surface transform style is flat.
      setLayerPropertiesForTesting(backFacingSurface.get(),  backfaceMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(100, 100), false); // surface transform style is flat.
      setLayerPropertiesForTesting(child1.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(100, 100), false);
      setLayerPropertiesForTesting(child2.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(100, 100), false);
  
      std::vector<scoped_refptr<Layer> > renderSurfaceLayerList;
      int dummyMaxTextureSize = 512;
      LayerTreeHostCommon::calculateDrawTransforms(parent.get(), parent->bounds(), 1, 1, dummyMaxTextureSize, renderSurfaceLayerList);
  
      // Verify which renderSurfaces were created.
      EXPECT_TRUE(frontFacingSurface->renderSurface());
      EXPECT_FALSE(backFacingSurface->renderSurface()); // because it should be culled
      EXPECT_FALSE(child1->renderSurface());
      EXPECT_FALSE(child2->renderSurface());
  
      // Verify the renderSurfaceLayerList. The back-facing surface should be culled.
      ASSERT_EQ(2u, renderSurfaceLayerList.size());
      EXPECT_EQ(parent->id(), renderSurfaceLayerList[0]->id());
      EXPECT_EQ(frontFacingSurface->id(), renderSurfaceLayerList[1]->id());
  
      // Verify root surface's layerList.
      ASSERT_EQ(1u, renderSurfaceLayerList[0]->renderSurface()->layerList().size());
      EXPECT_EQ(frontFacingSurface->id(), renderSurfaceLayerList[0]->renderSurface()->layerList()[0]->id());
  
      // Verify frontFacingSurface's layerList.
      ASSERT_EQ(2u, renderSurfaceLayerList[1]->renderSurface()->layerList().size());
      EXPECT_EQ(frontFacingSurface->id(), renderSurfaceLayerList[1]->renderSurface()->layerList()[0]->id());
      EXPECT_EQ(child1->id(), renderSurfaceLayerList[1]->renderSurface()->layerList()[1]->id());
  }
  
  TEST(LayerTreeHostCommonTest, verifyHitTestingForEmptyLayerList)
  {
      // Hit testing on an empty renderSurfaceLayerList should return a null pointer.
      DebugScopedSetImplThread thisScopeIsOnImplThread;
  
      std::vector<LayerImpl*> renderSurfaceLayerList;
  
      gfx::Point testPoint(0, 0);
      LayerImpl* resultLayer = LayerTreeHostCommon::findLayerThatIsHitByPoint(testPoint, renderSurfaceLayerList);
      EXPECT_FALSE(resultLayer);
  
      testPoint = gfx::Point(10, 20);
      resultLayer = LayerTreeHostCommon::findLayerThatIsHitByPoint(testPoint, renderSurfaceLayerList);
      EXPECT_FALSE(resultLayer);
  }
  
  TEST(LayerTreeHostCommonTest, verifyHitTestingForSingleLayer)
  {
      DebugScopedSetImplThread thisScopeIsOnImplThread;
  
      scoped_ptr<LayerImpl> root = LayerImpl::create(12345);
  
      WebTransformationMatrix identityMatrix;
      gfx::PointF anchor(0, 0);
      gfx::PointF position(0, 0);
      gfx::Size bounds(100, 100);
      setLayerPropertiesForTesting(root.get(), identityMatrix, identityMatrix, anchor, position, bounds, false);
      root->setDrawsContent(true);
  
      std::vector<LayerImpl*> renderSurfaceLayerList;
      int dummyMaxTextureSize = 512;
      LayerTreeHostCommon::calculateDrawTransforms(root.get(), root->bounds(), 1, 1, 0, dummyMaxTextureSize, renderSurfaceLayerList);
  
      // Sanity check the scenario we just created.
      ASSERT_EQ(1u, renderSurfaceLayerList.size());
      ASSERT_EQ(1u, root->renderSurface()->layerList().size());
  
      // Hit testing for a point outside the layer should return a null pointer.
      gfx::Point testPoint(101, 101);
      LayerImpl* resultLayer = LayerTreeHostCommon::findLayerThatIsHitByPoint(testPoint, renderSurfaceLayerList);
      EXPECT_FALSE(resultLayer);
  
      testPoint = gfx::Point(-1, -1);
      resultLayer = LayerTreeHostCommon::findLayerThatIsHitByPoint(testPoint, renderSurfaceLayerList);
      EXPECT_FALSE(resultLayer);
  
      // Hit testing for a point inside should return the root layer.
      testPoint = gfx::Point(1, 1);
      resultLayer = LayerTreeHostCommon::findLayerThatIsHitByPoint(testPoint, renderSurfaceLayerList);
      ASSERT_TRUE(resultLayer);
      EXPECT_EQ(12345, resultLayer->id());
  
      testPoint = gfx::Point(99, 99);
      resultLayer = LayerTreeHostCommon::findLayerThatIsHitByPoint(testPoint, renderSurfaceLayerList);
      ASSERT_TRUE(resultLayer);
      EXPECT_EQ(12345, resultLayer->id());
  }
  
  TEST(LayerTreeHostCommonTest, verifyHitTestingForUninvertibleTransform)
  {
      DebugScopedSetImplThread thisScopeIsOnImplThread;
  
      scoped_ptr<LayerImpl> root = LayerImpl::create(12345);
  
      WebTransformationMatrix uninvertibleTransform;
      uninvertibleTransform.setM11(0);
      uninvertibleTransform.setM22(0);
      uninvertibleTransform.setM33(0);
      uninvertibleTransform.setM44(0);
      ASSERT_FALSE(uninvertibleTransform.isInvertible());
  
      WebTransformationMatrix identityMatrix;
      gfx::PointF anchor(0, 0);
      gfx::PointF position(0, 0);
      gfx::Size bounds(100, 100);
      setLayerPropertiesForTesting(root.get(), uninvertibleTransform, identityMatrix, anchor, position, bounds, false);
      root->setDrawsContent(true);
  
      std::vector<LayerImpl*> renderSurfaceLayerList;
      int dummyMaxTextureSize = 512;
      LayerTreeHostCommon::calculateDrawTransforms(root.get(), root->bounds(), 1, 1, 0, dummyMaxTextureSize, renderSurfaceLayerList);
  
      // Sanity check the scenario we just created.
      ASSERT_EQ(1u, renderSurfaceLayerList.size());
      ASSERT_EQ(1u, root->renderSurface()->layerList().size());
      ASSERT_FALSE(root->screenSpaceTransform().isInvertible());
  
      // Hit testing any point should not hit the layer. If the invertible matrix is
      // accidentally ignored and treated like an identity, then the hit testing will
      // incorrectly hit the layer when it shouldn't.
      gfx::Point testPoint(1, 1);
      LayerImpl* resultLayer = LayerTreeHostCommon::findLayerThatIsHitByPoint(testPoint, renderSurfaceLayerList);
      EXPECT_FALSE(resultLayer);
  
      testPoint = gfx::Point(10, 10);
      resultLayer = LayerTreeHostCommon::findLayerThatIsHitByPoint(testPoint, renderSurfaceLayerList);
      EXPECT_FALSE(resultLayer);
  
      testPoint = gfx::Point(10, 30);
      resultLayer = LayerTreeHostCommon::findLayerThatIsHitByPoint(testPoint, renderSurfaceLayerList);
      EXPECT_FALSE(resultLayer);
  
      testPoint = gfx::Point(50, 50);
      resultLayer = LayerTreeHostCommon::findLayerThatIsHitByPoint(testPoint, renderSurfaceLayerList);
      EXPECT_FALSE(resultLayer);
  
      testPoint = gfx::Point(67, 48);
      resultLayer = LayerTreeHostCommon::findLayerThatIsHitByPoint(testPoint, renderSurfaceLayerList);
      EXPECT_FALSE(resultLayer);
  
      testPoint = gfx::Point(99, 99);
      resultLayer = LayerTreeHostCommon::findLayerThatIsHitByPoint(testPoint, renderSurfaceLayerList);
      EXPECT_FALSE(resultLayer);
  
      testPoint = gfx::Point(-1, -1);
      resultLayer = LayerTreeHostCommon::findLayerThatIsHitByPoint(testPoint, renderSurfaceLayerList);
      EXPECT_FALSE(resultLayer);
  }
  
  TEST(LayerTreeHostCommonTest, verifyHitTestingForSinglePositionedLayer)
  {
      DebugScopedSetImplThread thisScopeIsOnImplThread;
  
      scoped_ptr<LayerImpl> root = LayerImpl::create(12345);
  
      WebTransformationMatrix identityMatrix;
      gfx::PointF anchor(0, 0);
      gfx::PointF position(50, 50); // this layer is positioned, and hit testing should correctly know where the layer is located.
      gfx::Size bounds(100, 100);
      setLayerPropertiesForTesting(root.get(), identityMatrix, identityMatrix, anchor, position, bounds, false);
      root->setDrawsContent(true);
  
      std::vector<LayerImpl*> renderSurfaceLayerList;
      int dummyMaxTextureSize = 512;
      LayerTreeHostCommon::calculateDrawTransforms(root.get(), root->bounds(), 1, 1, 0, dummyMaxTextureSize, renderSurfaceLayerList);
  
      // Sanity check the scenario we just created.
      ASSERT_EQ(1u, renderSurfaceLayerList.size());
      ASSERT_EQ(1u, root->renderSurface()->layerList().size());
  
      // Hit testing for a point outside the layer should return a null pointer.
      gfx::Point testPoint(49, 49);
      LayerImpl* resultLayer = LayerTreeHostCommon::findLayerThatIsHitByPoint(testPoint, renderSurfaceLayerList);
      EXPECT_FALSE(resultLayer);
  
      // Even though the layer exists at (101, 101), it should not be visible there since the root renderSurface would clamp it.
      testPoint = gfx::Point(101, 101);
      resultLayer = LayerTreeHostCommon::findLayerThatIsHitByPoint(testPoint, renderSurfaceLayerList);
      EXPECT_FALSE(resultLayer);
  
      // Hit testing for a point inside should return the root layer.
      testPoint = gfx::Point(51, 51);
      resultLayer = LayerTreeHostCommon::findLayerThatIsHitByPoint(testPoint, renderSurfaceLayerList);
      ASSERT_TRUE(resultLayer);
      EXPECT_EQ(12345, resultLayer->id());
  
      testPoint = gfx::Point(99, 99);
      resultLayer = LayerTreeHostCommon::findLayerThatIsHitByPoint(testPoint, renderSurfaceLayerList);
      ASSERT_TRUE(resultLayer);
      EXPECT_EQ(12345, resultLayer->id());
  }
  
  TEST(LayerTreeHostCommonTest, verifyHitTestingForSingleRotatedLayer)
  {
      DebugScopedSetImplThread thisScopeIsOnImplThread;
  
      scoped_ptr<LayerImpl> root = LayerImpl::create(12345);
  
      WebTransformationMatrix identityMatrix;
      WebTransformationMatrix rotation45DegreesAboutCenter;
      rotation45DegreesAboutCenter.translate(50, 50);
      rotation45DegreesAboutCenter.rotate3d(0, 0, 45);
      rotation45DegreesAboutCenter.translate(-50, -50);
      gfx::PointF anchor(0, 0);
      gfx::PointF position(0, 0);
      gfx::Size bounds(100, 100);
      setLayerPropertiesForTesting(root.get(), rotation45DegreesAboutCenter, identityMatrix, anchor, position, bounds, false);
      root->setDrawsContent(true);
  
      std::vector<LayerImpl*> renderSurfaceLayerList;
      int dummyMaxTextureSize = 512;
      LayerTreeHostCommon::calculateDrawTransforms(root.get(), root->bounds(), 1, 1, 0, dummyMaxTextureSize, renderSurfaceLayerList);
  
      // Sanity check the scenario we just created.
      ASSERT_EQ(1u, renderSurfaceLayerList.size());
      ASSERT_EQ(1u, root->renderSurface()->layerList().size());
  
      // Hit testing for points outside the layer.
      // These corners would have been inside the un-transformed layer, but they should not hit the correctly transformed layer.
      gfx::Point testPoint(99, 99);
      LayerImpl* resultLayer = LayerTreeHostCommon::findLayerThatIsHitByPoint(testPoint, renderSurfaceLayerList);
      EXPECT_FALSE(resultLayer);
  
      testPoint = gfx::Point(1, 1);
      resultLayer = LayerTreeHostCommon::findLayerThatIsHitByPoint(testPoint, renderSurfaceLayerList);
      EXPECT_FALSE(resultLayer);
  
      // Hit testing for a point inside should return the root layer.
      testPoint = gfx::Point(1, 50);
      resultLayer = LayerTreeHostCommon::findLayerThatIsHitByPoint(testPoint, renderSurfaceLayerList);
      ASSERT_TRUE(resultLayer);
      EXPECT_EQ(12345, resultLayer->id());
  
      // Hit testing the corners that would overlap the unclipped layer, but are outside the clipped region.
      testPoint = gfx::Point(50, -1);
      resultLayer = LayerTreeHostCommon::findLayerThatIsHitByPoint(testPoint, renderSurfaceLayerList);
      ASSERT_FALSE(resultLayer);
  
      testPoint = gfx::Point(-1, 50);
      resultLayer = LayerTreeHostCommon::findLayerThatIsHitByPoint(testPoint, renderSurfaceLayerList);
      ASSERT_FALSE(resultLayer);
  }
  
  TEST(LayerTreeHostCommonTest, verifyHitTestingForSinglePerspectiveLayer)
  {
      DebugScopedSetImplThread thisScopeIsOnImplThread;
  
      scoped_ptr<LayerImpl> root = LayerImpl::create(12345);
  
      WebTransformationMatrix identityMatrix;
  
      // perspectiveProjectionAboutCenter * translationByZ is designed so that the 100 x 100 layer becomes 50 x 50, and remains centered at (50, 50).
      WebTransformationMatrix perspectiveProjectionAboutCenter;
      perspectiveProjectionAboutCenter.translate(50, 50);
      perspectiveProjectionAboutCenter.applyPerspective(1);
      perspectiveProjectionAboutCenter.translate(-50, -50);
      WebTransformationMatrix translationByZ;
      translationByZ.translate3d(0, 0, -1);
  
      gfx::PointF anchor(0, 0);
      gfx::PointF position(0, 0);
      gfx::Size bounds(100, 100);
      setLayerPropertiesForTesting(root.get(), perspectiveProjectionAboutCenter * translationByZ, identityMatrix, anchor, position, bounds, false);
      root->setDrawsContent(true);
  
      std::vector<LayerImpl*> renderSurfaceLayerList;
      int dummyMaxTextureSize = 512;
      LayerTreeHostCommon::calculateDrawTransforms(root.get(), root->bounds(), 1, 1, 0, dummyMaxTextureSize, renderSurfaceLayerList);
  
      // Sanity check the scenario we just created.
      ASSERT_EQ(1u, renderSurfaceLayerList.size());
      ASSERT_EQ(1u, root->renderSurface()->layerList().size());
  
      // Hit testing for points outside the layer.
      // These corners would have been inside the un-transformed layer, but they should not hit the correctly transformed layer.
      gfx::Point testPoint(24, 24);
      LayerImpl* resultLayer = LayerTreeHostCommon::findLayerThatIsHitByPoint(testPoint, renderSurfaceLayerList);
      EXPECT_FALSE(resultLayer);
  
      testPoint = gfx::Point(76, 76);
      resultLayer = LayerTreeHostCommon::findLayerThatIsHitByPoint(testPoint, renderSurfaceLayerList);
      EXPECT_FALSE(resultLayer);
  
      // Hit testing for a point inside should return the root layer.
      testPoint = gfx::Point(26, 26);
      resultLayer = LayerTreeHostCommon::findLayerThatIsHitByPoint(testPoint, renderSurfaceLayerList);
      ASSERT_TRUE(resultLayer);
      EXPECT_EQ(12345, resultLayer->id());
  
      testPoint = gfx::Point(74, 74);
      resultLayer = LayerTreeHostCommon::findLayerThatIsHitByPoint(testPoint, renderSurfaceLayerList);
      ASSERT_TRUE(resultLayer);
      EXPECT_EQ(12345, resultLayer->id());
  }
  
  TEST(LayerTreeHostCommonTest, verifyHitTestingForSingleLayerWithScaledContents)
  {
      // A layer's visibleContentRect is actually in the layer's content space. The
      // screenSpaceTransform converts from the layer's origin space to screen space. This
      // test makes sure that hit testing works correctly accounts for the contents scale.
      // A contentsScale that is not 1 effectively forces a non-identity transform between
      // layer's content space and layer's origin space. The hit testing code must take this into account.
      //
      // To test this, the layer is positioned at (25, 25), and is size (50, 50). If
      // contentsScale is ignored, then hit testing will mis-interpret the visibleContentRect
      // as being larger than the actual bounds of the layer.
      //
      DebugScopedSetImplThread thisScopeIsOnImplThread;
  
      scoped_ptr<LayerImpl> root = LayerImpl::create(1);
  
      WebTransformationMatrix identityMatrix;
      gfx::PointF anchor(0, 0);
  
      setLayerPropertiesForTesting(root.get(), identityMatrix, identityMatrix, anchor, gfx::PointF(0, 0), gfx::Size(100, 100), false);
  
      {
          gfx::PointF position(25, 25);
          gfx::Size bounds(50, 50);
          scoped_ptr<LayerImpl> testLayer = LayerImpl::create(12345);
          setLayerPropertiesForTesting(testLayer.get(), identityMatrix, identityMatrix, anchor, position, bounds, false);
  
          // override contentBounds and contentsScale
          testLayer->setContentBounds(gfx::Size(100, 100));
          testLayer->setContentsScale(2, 2);
  
          testLayer->setDrawsContent(true);
          root->addChild(testLayer.Pass());
      }
  
      std::vector<LayerImpl*> renderSurfaceLayerList;
      int dummyMaxTextureSize = 512;
      LayerTreeHostCommon::calculateDrawTransforms(root.get(), root->bounds(), 1, 1, 0, dummyMaxTextureSize, renderSurfaceLayerList);
  
      // Sanity check the scenario we just created.
      // The visibleContentRect for testLayer is actually 100x100, even though its layout size is 50x50, positioned at 25x25.
      LayerImpl* testLayer = root->children()[0];
      EXPECT_RECT_EQ(gfx::Rect(gfx::Point(), gfx::Size(100, 100)), testLayer->visibleContentRect());
      ASSERT_EQ(1u, renderSurfaceLayerList.size());
      ASSERT_EQ(1u, root->renderSurface()->layerList().size());
  
      // Hit testing for a point outside the layer should return a null pointer (the root layer does not draw content, so it will not be hit tested either).
      gfx::Point testPoint(101, 101);
      LayerImpl* resultLayer = LayerTreeHostCommon::findLayerThatIsHitByPoint(testPoint, renderSurfaceLayerList);
      EXPECT_FALSE(resultLayer);
  
      testPoint = gfx::Point(24, 24);
      resultLayer = LayerTreeHostCommon::findLayerThatIsHitByPoint(testPoint, renderSurfaceLayerList);
      EXPECT_FALSE(resultLayer);
  
      testPoint = gfx::Point(76, 76);
      resultLayer = LayerTreeHostCommon::findLayerThatIsHitByPoint(testPoint, renderSurfaceLayerList);
      EXPECT_FALSE(resultLayer);
  
      // Hit testing for a point inside should return the test layer.
      testPoint = gfx::Point(26, 26);
      resultLayer = LayerTreeHostCommon::findLayerThatIsHitByPoint(testPoint, renderSurfaceLayerList);
      ASSERT_TRUE(resultLayer);
      EXPECT_EQ(12345, resultLayer->id());
  
      testPoint = gfx::Point(74, 74);
      resultLayer = LayerTreeHostCommon::findLayerThatIsHitByPoint(testPoint, renderSurfaceLayerList);
      ASSERT_TRUE(resultLayer);
      EXPECT_EQ(12345, resultLayer->id());
  }
  
  TEST(LayerTreeHostCommonTest, verifyHitTestingForSimpleClippedLayer)
  {
      // Test that hit-testing will only work for the visible portion of a layer, and not
      // the entire layer bounds. Here we just test the simple axis-aligned case.
      DebugScopedSetImplThread thisScopeIsOnImplThread;
  
      WebTransformationMatrix identityMatrix;
      gfx::PointF anchor(0, 0);
  
      scoped_ptr<LayerImpl> root = LayerImpl::create(1);
      setLayerPropertiesForTesting(root.get(), identityMatrix, identityMatrix, anchor, gfx::PointF(0, 0), gfx::Size(100, 100), false);
  
      {
          scoped_ptr<LayerImpl> clippingLayer = LayerImpl::create(123);
          gfx::PointF position(25, 25); // this layer is positioned, and hit testing should correctly know where the layer is located.
          gfx::Size bounds(50, 50);
          setLayerPropertiesForTesting(clippingLayer.get(), identityMatrix, identityMatrix, anchor, position, bounds, false);
          clippingLayer->setMasksToBounds(true);
  
          scoped_ptr<LayerImpl> child = LayerImpl::create(456);
          position = gfx::PointF(-50, -50);
          bounds = gfx::Size(300, 300);
          setLayerPropertiesForTesting(child.get(), identityMatrix, identityMatrix, anchor, position, bounds, false);
          child->setDrawsContent(true);
          clippingLayer->addChild(child.Pass());
          root->addChild(clippingLayer.Pass());
      }
  
      std::vector<LayerImpl*> renderSurfaceLayerList;
      int dummyMaxTextureSize = 512;
      LayerTreeHostCommon::calculateDrawTransforms(root.get(), root->bounds(), 1, 1, 0, dummyMaxTextureSize, renderSurfaceLayerList);
  
      // Sanity check the scenario we just created.
      ASSERT_EQ(1u, renderSurfaceLayerList.size());
      ASSERT_EQ(1u, root->renderSurface()->layerList().size());
      ASSERT_EQ(456, root->renderSurface()->layerList()[0]->id());
  
      // Hit testing for a point outside the layer should return a null pointer.
      // Despite the child layer being very large, it should be clipped to the root layer's bounds.
      gfx::Point testPoint(24, 24);
      LayerImpl* resultLayer = LayerTreeHostCommon::findLayerThatIsHitByPoint(testPoint, renderSurfaceLayerList);
      EXPECT_FALSE(resultLayer);
  
      // Even though the layer exists at (101, 101), it should not be visible there since the clippingLayer would clamp it.
      testPoint = gfx::Point(76, 76);
      resultLayer = LayerTreeHostCommon::findLayerThatIsHitByPoint(testPoint, renderSurfaceLayerList);
      EXPECT_FALSE(resultLayer);
  
      // Hit testing for a point inside should return the child layer.
      testPoint = gfx::Point(26, 26);
      resultLayer = LayerTreeHostCommon::findLayerThatIsHitByPoint(testPoint, renderSurfaceLayerList);
      ASSERT_TRUE(resultLayer);
      EXPECT_EQ(456, resultLayer->id());
  
      testPoint = gfx::Point(74, 74);
      resultLayer = LayerTreeHostCommon::findLayerThatIsHitByPoint(testPoint, renderSurfaceLayerList);
      ASSERT_TRUE(resultLayer);
      EXPECT_EQ(456, resultLayer->id());
  }
  
  TEST(LayerTreeHostCommonTest, verifyHitTestingForMultiClippedRotatedLayer)
  {
      // This test checks whether hit testing correctly avoids hit testing with multiple
      // ancestors that clip in non axis-aligned ways. To pass this test, the hit testing
      // algorithm needs to recognize that multiple parent layers may clip the layer, and
      // should not actually hit those clipped areas.
      //
      // The child and grandChild layers are both initialized to clip the rotatedLeaf. The
      // child layer is rotated about the top-left corner, so that the root + child clips
      // combined create a triangle. The rotatedLeaf will only be visible where it overlaps
      // this triangle.
      //
      DebugScopedSetImplThread thisScopeIsOnImplThread;
  
      scoped_ptr<LayerImpl> root = LayerImpl::create(123);
  
      WebTransformationMatrix identityMatrix;
      gfx::PointF anchor(0, 0);
      gfx::PointF position(0, 0);
      gfx::Size bounds(100, 100);
      setLayerPropertiesForTesting(root.get(), identityMatrix, identityMatrix, anchor, position, bounds, false);
      root->setMasksToBounds(true);
  
      {
          scoped_ptr<LayerImpl> child = LayerImpl::create(456);
          scoped_ptr<LayerImpl> grandChild = LayerImpl::create(789);
          scoped_ptr<LayerImpl> rotatedLeaf = LayerImpl::create(2468);
  
          position = gfx::PointF(10, 10);
          bounds = gfx::Size(80, 80);
          setLayerPropertiesForTesting(child.get(), identityMatrix, identityMatrix, anchor, position, bounds, false);
          child->setMasksToBounds(true);
          
          WebTransformationMatrix rotation45DegreesAboutCorner;
          rotation45DegreesAboutCorner.rotate3d(0, 0, 45);
  
          position = gfx::PointF(0, 0); // remember, positioned with respect to its parent which is already at 10, 10
          bounds = gfx::Size(200, 200); // to ensure it covers at least sqrt(2) * 100.
          setLayerPropertiesForTesting(grandChild.get(), rotation45DegreesAboutCorner, identityMatrix, anchor, position, bounds, false);
          grandChild->setMasksToBounds(true);
  
          // Rotates about the center of the layer
          WebTransformationMatrix rotatedLeafTransform;
          rotatedLeafTransform.translate(-10, -10); // cancel out the grandParent's position
          rotatedLeafTransform.rotate3d(0, 0, -45); // cancel out the corner 45-degree rotation of the parent.
          rotatedLeafTransform.translate(50, 50);
          rotatedLeafTransform.rotate3d(0, 0, 45);
          rotatedLeafTransform.translate(-50, -50);
          position = gfx::PointF(0, 0);
          bounds = gfx::Size(100, 100);
          setLayerPropertiesForTesting(rotatedLeaf.get(), rotatedLeafTransform, identityMatrix, anchor, position, bounds, false);
          rotatedLeaf->setDrawsContent(true);
  
          grandChild->addChild(rotatedLeaf.Pass());
          child->addChild(grandChild.Pass());
          root->addChild(child.Pass());
      }
  
      std::vector<LayerImpl*> renderSurfaceLayerList;
      int dummyMaxTextureSize = 512;
      LayerTreeHostCommon::calculateDrawTransforms(root.get(), root->bounds(), 1, 1, 0, dummyMaxTextureSize, renderSurfaceLayerList);
  
      // Sanity check the scenario we just created.
      // The grandChild is expected to create a renderSurface because it masksToBounds and is not axis aligned.
      ASSERT_EQ(2u, renderSurfaceLayerList.size());
      ASSERT_EQ(1u, renderSurfaceLayerList[0]->renderSurface()->layerList().size());
      ASSERT_EQ(789, renderSurfaceLayerList[0]->renderSurface()->layerList()[0]->id()); // grandChild's surface.
      ASSERT_EQ(1u, renderSurfaceLayerList[1]->renderSurface()->layerList().size());
      ASSERT_EQ(2468, renderSurfaceLayerList[1]->renderSurface()->layerList()[0]->id());
  
      // (11, 89) is close to the the bottom left corner within the clip, but it is not inside the layer.
      gfx::Point testPoint(11, 89);
      LayerImpl* resultLayer = LayerTreeHostCommon::findLayerThatIsHitByPoint(testPoint, renderSurfaceLayerList);
      EXPECT_FALSE(resultLayer);
  
      // Closer inwards from the bottom left will overlap the layer.
      testPoint = gfx::Point(25, 75);
      resultLayer = LayerTreeHostCommon::findLayerThatIsHitByPoint(testPoint, renderSurfaceLayerList);
      ASSERT_TRUE(resultLayer);
      EXPECT_EQ(2468, resultLayer->id());
  
      // (4, 50) is inside the unclipped layer, but that corner of the layer should be
      // clipped away by the grandParent and should not get hit. If hit testing blindly uses
      // visibleContentRect without considering how parent may clip the layer, then hit
      // testing would accidentally think that the point successfully hits the layer.
      testPoint = gfx::Point(4, 50);
      resultLayer = LayerTreeHostCommon::findLayerThatIsHitByPoint(testPoint, renderSurfaceLayerList);
      EXPECT_FALSE(resultLayer);
  
      // (11, 50) is inside the layer and within the clipped area.
      testPoint = gfx::Point(11, 50);
      resultLayer = LayerTreeHostCommon::findLayerThatIsHitByPoint(testPoint, renderSurfaceLayerList);
      ASSERT_TRUE(resultLayer);
      EXPECT_EQ(2468, resultLayer->id());
  
      // Around the middle, just to the right and up, would have hit the layer except that
      // that area should be clipped away by the parent.
      testPoint = gfx::Point(51, 51);
      resultLayer = LayerTreeHostCommon::findLayerThatIsHitByPoint(testPoint, renderSurfaceLayerList);
      EXPECT_FALSE(resultLayer);
  
      // Around the middle, just to the left and down, should successfully hit the layer.
      testPoint = gfx::Point(49, 51);
      resultLayer = LayerTreeHostCommon::findLayerThatIsHitByPoint(testPoint, renderSurfaceLayerList);
      ASSERT_TRUE(resultLayer);
      EXPECT_EQ(2468, resultLayer->id());
  }
  
  TEST(LayerTreeHostCommonTest, verifyHitTestingForNonClippingIntermediateLayer)
  {
      // This test checks that hit testing code does not accidentally clip to layer
      // bounds for a layer that actually does not clip.
      DebugScopedSetImplThread thisScopeIsOnImplThread;
  
      WebTransformationMatrix identityMatrix;
      gfx::PointF anchor(0, 0);
  
      scoped_ptr<LayerImpl> root = LayerImpl::create(1);
      setLayerPropertiesForTesting(root.get(), identityMatrix, identityMatrix, anchor, gfx::PointF(0, 0), gfx::Size(100, 100), false);
  
      {
          scoped_ptr<LayerImpl> intermediateLayer = LayerImpl::create(123);
          gfx::PointF position(10, 10); // this layer is positioned, and hit testing should correctly know where the layer is located.
          gfx::Size bounds(50, 50);
          setLayerPropertiesForTesting(intermediateLayer.get(), identityMatrix, identityMatrix, anchor, position, bounds, false);
          // Sanity check the intermediate layer should not clip.
          ASSERT_FALSE(intermediateLayer->masksToBounds());
          ASSERT_FALSE(intermediateLayer->maskLayer());
  
          // The child of the intermediateLayer is translated so that it does not overlap intermediateLayer at all.
          // If child is incorrectly clipped, we would not be able to hit it successfully.
          scoped_ptr<LayerImpl> child = LayerImpl::create(456);
          position = gfx::PointF(60, 60); // 70, 70 in screen space
          bounds = gfx::Size(20, 20);
          setLayerPropertiesForTesting(child.get(), identityMatrix, identityMatrix, anchor, position, bounds, false);
          child->setDrawsContent(true);
          intermediateLayer->addChild(child.Pass());
          root->addChild(intermediateLayer.Pass());
      }
  
      std::vector<LayerImpl*> renderSurfaceLayerList;
      int dummyMaxTextureSize = 512;
      LayerTreeHostCommon::calculateDrawTransforms(root.get(), root->bounds(), 1, 1, 0, dummyMaxTextureSize, renderSurfaceLayerList);
  
      // Sanity check the scenario we just created.
      ASSERT_EQ(1u, renderSurfaceLayerList.size());
      ASSERT_EQ(1u, root->renderSurface()->layerList().size());
      ASSERT_EQ(456, root->renderSurface()->layerList()[0]->id());
  
      // Hit testing for a point outside the layer should return a null pointer.
      gfx::Point testPoint(69, 69);
      LayerImpl* resultLayer = LayerTreeHostCommon::findLayerThatIsHitByPoint(testPoint, renderSurfaceLayerList);
      EXPECT_FALSE(resultLayer);
  
      testPoint = gfx::Point(91, 91);
      resultLayer = LayerTreeHostCommon::findLayerThatIsHitByPoint(testPoint, renderSurfaceLayerList);
      EXPECT_FALSE(resultLayer);
  
      // Hit testing for a point inside should return the child layer.
      testPoint = gfx::Point(71, 71);
      resultLayer = LayerTreeHostCommon::findLayerThatIsHitByPoint(testPoint, renderSurfaceLayerList);
      ASSERT_TRUE(resultLayer);
      EXPECT_EQ(456, resultLayer->id());
  
      testPoint = gfx::Point(89, 89);
      resultLayer = LayerTreeHostCommon::findLayerThatIsHitByPoint(testPoint, renderSurfaceLayerList);
      ASSERT_TRUE(resultLayer);
      EXPECT_EQ(456, resultLayer->id());
  }
  
  
  TEST(LayerTreeHostCommonTest, verifyHitTestingForMultipleLayers)
  {
      DebugScopedSetImplThread thisScopeIsOnImplThread;
  
      scoped_ptr<LayerImpl> root = LayerImpl::create(1);
  
      WebTransformationMatrix identityMatrix;
      gfx::PointF anchor(0, 0);
      gfx::PointF position(0, 0);
      gfx::Size bounds(100, 100);
      setLayerPropertiesForTesting(root.get(), identityMatrix, identityMatrix, anchor, position, bounds, false);
      root->setDrawsContent(true);
  
      {
          // child 1 and child2 are initialized to overlap between x=50 and x=60.
          // grandChild is set to overlap both child1 and child2 between y=50 and y=60.
          // The expected stacking order is:
          //   (front) child2, (second) grandChild, (third) child1, and (back) the root layer behind all other layers.
  
          scoped_ptr<LayerImpl> child1 = LayerImpl::create(2);
          scoped_ptr<LayerImpl> child2 = LayerImpl::create(3);
          scoped_ptr<LayerImpl> grandChild1 = LayerImpl::create(4);
  
          position = gfx::PointF(10, 10);
          bounds = gfx::Size(50, 50);
          setLayerPropertiesForTesting(child1.get(), identityMatrix, identityMatrix, anchor, position, bounds, false);
          child1->setDrawsContent(true);
  
          position = gfx::PointF(50, 10);
          bounds = gfx::Size(50, 50);
          setLayerPropertiesForTesting(child2.get(), identityMatrix, identityMatrix, anchor, position, bounds, false);
          child2->setDrawsContent(true);
  
          // Remember that grandChild is positioned with respect to its parent (i.e. child1).
          // In screen space, the intended position is (10, 50), with size 100 x 50.
          position = gfx::PointF(0, 40);
          bounds = gfx::Size(100, 50);
          setLayerPropertiesForTesting(grandChild1.get(), identityMatrix, identityMatrix, anchor, position, bounds, false);
          grandChild1->setDrawsContent(true);
  
          child1->addChild(grandChild1.Pass());
          root->addChild(child1.Pass());
          root->addChild(child2.Pass());
      }
  
      LayerImpl* child1 = root->children()[0];
      LayerImpl* child2 = root->children()[1];
      LayerImpl* grandChild1 = child1->children()[0];
  
      std::vector<LayerImpl*> renderSurfaceLayerList;
      int dummyMaxTextureSize = 512;
      LayerTreeHostCommon::calculateDrawTransforms(root.get(), root->bounds(), 1, 1, 0, dummyMaxTextureSize, renderSurfaceLayerList);
  
      // Sanity check the scenario we just created.
      ASSERT_TRUE(child1);
      ASSERT_TRUE(child2);
      ASSERT_TRUE(grandChild1);
      ASSERT_EQ(1u, renderSurfaceLayerList.size());
      ASSERT_EQ(4u, root->renderSurface()->layerList().size());
      ASSERT_EQ(1, root->renderSurface()->layerList()[0]->id()); // root layer
      ASSERT_EQ(2, root->renderSurface()->layerList()[1]->id()); // child1
      ASSERT_EQ(4, root->renderSurface()->layerList()[2]->id()); // grandChild1
      ASSERT_EQ(3, root->renderSurface()->layerList()[3]->id()); // child2
  
      // Nothing overlaps the rootLayer at (1, 1), so hit testing there should find the root layer.
      gfx::Point testPoint = gfx::Point(1, 1);
      LayerImpl* resultLayer = LayerTreeHostCommon::findLayerThatIsHitByPoint(testPoint, renderSurfaceLayerList);
      ASSERT_TRUE(resultLayer);
      EXPECT_EQ(1, resultLayer->id());
  
      // At (15, 15), child1 and root are the only layers. child1 is expected to be on top.
      testPoint = gfx::Point(15, 15);
      resultLayer = LayerTreeHostCommon::findLayerThatIsHitByPoint(testPoint, renderSurfaceLayerList);
      ASSERT_TRUE(resultLayer);
      EXPECT_EQ(2, resultLayer->id());
  
      // At (51, 20), child1 and child2 overlap. child2 is expected to be on top.
      testPoint = gfx::Point(51, 20);
      resultLayer = LayerTreeHostCommon::findLayerThatIsHitByPoint(testPoint, renderSurfaceLayerList);
      ASSERT_TRUE(resultLayer);
      EXPECT_EQ(3, resultLayer->id());
  
      // At (80, 51), child2 and grandChild1 overlap. child2 is expected to be on top.
      testPoint = gfx::Point(80, 51);
      resultLayer = LayerTreeHostCommon::findLayerThatIsHitByPoint(testPoint, renderSurfaceLayerList);
      ASSERT_TRUE(resultLayer);
      EXPECT_EQ(3, resultLayer->id());
  
      // At (51, 51), all layers overlap each other. child2 is expected to be on top of all other layers.
      testPoint = gfx::Point(51, 51);
      resultLayer = LayerTreeHostCommon::findLayerThatIsHitByPoint(testPoint, renderSurfaceLayerList);
      ASSERT_TRUE(resultLayer);
      EXPECT_EQ(3, resultLayer->id());
  
      // At (20, 51), child1 and grandChild1 overlap. grandChild1 is expected to be on top.
      testPoint = gfx::Point(20, 51);
      resultLayer = LayerTreeHostCommon::findLayerThatIsHitByPoint(testPoint, renderSurfaceLayerList);
      ASSERT_TRUE(resultLayer);
      EXPECT_EQ(4, resultLayer->id());
  }
  
  TEST(LayerTreeHostCommonTest, verifyHitTestingForMultipleLayerLists)
  {
      //
      // The geometry is set up similarly to the previous case, but
      // all layers are forced to be renderSurfaces now.
      //
      DebugScopedSetImplThread thisScopeIsOnImplThread;
  
      scoped_ptr<LayerImpl> root = LayerImpl::create(1);
  
      WebTransformationMatrix identityMatrix;
      gfx::PointF anchor(0, 0);
      gfx::PointF position(0, 0);
      gfx::Size bounds(100, 100);
      setLayerPropertiesForTesting(root.get(), identityMatrix, identityMatrix, anchor, position, bounds, false);
      root->setDrawsContent(true);
  
      {
          // child 1 and child2 are initialized to overlap between x=50 and x=60.
          // grandChild is set to overlap both child1 and child2 between y=50 and y=60.
          // The expected stacking order is:
          //   (front) child2, (second) grandChild, (third) child1, and (back) the root layer behind all other layers.
  
          scoped_ptr<LayerImpl> child1 = LayerImpl::create(2);
          scoped_ptr<LayerImpl> child2 = LayerImpl::create(3);
          scoped_ptr<LayerImpl> grandChild1 = LayerImpl::create(4);
  
          position = gfx::PointF(10, 10);
          bounds = gfx::Size(50, 50);
          setLayerPropertiesForTesting(child1.get(), identityMatrix, identityMatrix, anchor, position, bounds, false);
          child1->setDrawsContent(true);
          child1->setForceRenderSurface(true);
  
          position = gfx::PointF(50, 10);
          bounds = gfx::Size(50, 50);
          setLayerPropertiesForTesting(child2.get(), identityMatrix, identityMatrix, anchor, position, bounds, false);
          child2->setDrawsContent(true);
          child2->setForceRenderSurface(true);
  
          // Remember that grandChild is positioned with respect to its parent (i.e. child1).
          // In screen space, the intended position is (10, 50), with size 100 x 50.
          position = gfx::PointF(0, 40);
          bounds = gfx::Size(100, 50);
          setLayerPropertiesForTesting(grandChild1.get(), identityMatrix, identityMatrix, anchor, position, bounds, false);
          grandChild1->setDrawsContent(true);
          grandChild1->setForceRenderSurface(true);
  
          child1->addChild(grandChild1.Pass());
          root->addChild(child1.Pass());
          root->addChild(child2.Pass());
      }
  
      LayerImpl* child1 = root->children()[0];
      LayerImpl* child2 = root->children()[1];
      LayerImpl* grandChild1 = child1->children()[0];
  
      std::vector<LayerImpl*> renderSurfaceLayerList;
      int dummyMaxTextureSize = 512;
      LayerTreeHostCommon::calculateDrawTransforms(root.get(), root->bounds(), 1, 1, 0, dummyMaxTextureSize, renderSurfaceLayerList);
  
      // Sanity check the scenario we just created.
      ASSERT_TRUE(child1);
      ASSERT_TRUE(child2);
      ASSERT_TRUE(grandChild1);
      ASSERT_TRUE(child1->renderSurface());
      ASSERT_TRUE(child2->renderSurface());
      ASSERT_TRUE(grandChild1->renderSurface());
      ASSERT_EQ(4u, renderSurfaceLayerList.size());
      ASSERT_EQ(3u, root->renderSurface()->layerList().size()); // The root surface has the root layer, and child1's and child2's renderSurfaces.
      ASSERT_EQ(2u, child1->renderSurface()->layerList().size()); // The child1 surface has the child1 layer and grandChild1's renderSurface.
      ASSERT_EQ(1u, child2->renderSurface()->layerList().size());
      ASSERT_EQ(1u, grandChild1->renderSurface()->layerList().size());
      ASSERT_EQ(1, renderSurfaceLayerList[0]->id()); // root layer
      ASSERT_EQ(2, renderSurfaceLayerList[1]->id()); // child1
      ASSERT_EQ(4, renderSurfaceLayerList[2]->id()); // grandChild1
      ASSERT_EQ(3, renderSurfaceLayerList[3]->id()); // child2
  
      // Nothing overlaps the rootLayer at (1, 1), so hit testing there should find the root layer.
      gfx::Point testPoint = gfx::Point(1, 1);
      LayerImpl* resultLayer = LayerTreeHostCommon::findLayerThatIsHitByPoint(testPoint, renderSurfaceLayerList);
      ASSERT_TRUE(resultLayer);
      EXPECT_EQ(1, resultLayer->id());
  
      // At (15, 15), child1 and root are the only layers. child1 is expected to be on top.
      testPoint = gfx::Point(15, 15);
      resultLayer = LayerTreeHostCommon::findLayerThatIsHitByPoint(testPoint, renderSurfaceLayerList);
      ASSERT_TRUE(resultLayer);
      EXPECT_EQ(2, resultLayer->id());
  
      // At (51, 20), child1 and child2 overlap. child2 is expected to be on top.
      testPoint = gfx::Point(51, 20);
      resultLayer = LayerTreeHostCommon::findLayerThatIsHitByPoint(testPoint, renderSurfaceLayerList);
      ASSERT_TRUE(resultLayer);
      EXPECT_EQ(3, resultLayer->id());
  
      // At (80, 51), child2 and grandChild1 overlap. child2 is expected to be on top.
      testPoint = gfx::Point(80, 51);
      resultLayer = LayerTreeHostCommon::findLayerThatIsHitByPoint(testPoint, renderSurfaceLayerList);
      ASSERT_TRUE(resultLayer);
      EXPECT_EQ(3, resultLayer->id());
  
      // At (51, 51), all layers overlap each other. child2 is expected to be on top of all other layers.
      testPoint = gfx::Point(51, 51);
      resultLayer = LayerTreeHostCommon::findLayerThatIsHitByPoint(testPoint, renderSurfaceLayerList);
      ASSERT_TRUE(resultLayer);
      EXPECT_EQ(3, resultLayer->id());
  
      // At (20, 51), child1 and grandChild1 overlap. grandChild1 is expected to be on top.
      testPoint = gfx::Point(20, 51);
      resultLayer = LayerTreeHostCommon::findLayerThatIsHitByPoint(testPoint, renderSurfaceLayerList);
      ASSERT_TRUE(resultLayer);
      EXPECT_EQ(4, resultLayer->id());
  }
  
  class NoScaleContentLayer : public ContentLayer
  {
  public:
      static scoped_refptr<NoScaleContentLayer> create(ContentLayerClient* client) { return make_scoped_refptr(new NoScaleContentLayer(client)); }
  
      virtual gfx::Size contentBounds() const OVERRIDE { return bounds(); }
      virtual float contentsScaleX() const OVERRIDE { return 1.0; }
      virtual float contentsScaleY() const OVERRIDE { return 1.0; }
  
  protected:
      explicit NoScaleContentLayer(ContentLayerClient* client) : ContentLayer(client) { }
      virtual ~NoScaleContentLayer() { }
  };
  
  scoped_refptr<NoScaleContentLayer> createNoScaleDrawableContentLayer(ContentLayerClient* delegate)
  {
      scoped_refptr<NoScaleContentLayer> toReturn = NoScaleContentLayer::create(delegate);
      toReturn->setIsDrawable(true);
      return toReturn;
  }
  
  TEST(LayerTreeHostCommonTest, verifyLayerTransformsInHighDPI)
  {
      // Verify draw and screen space transforms of layers not in a surface.
      MockContentLayerClient delegate;
      WebTransformationMatrix identityMatrix;
  
      scoped_refptr<ContentLayer> parent = createDrawableContentLayer(&delegate);
      setLayerPropertiesForTesting(parent.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(100, 100), true);
  
      scoped_refptr<ContentLayer> child = createDrawableContentLayer(&delegate);
      setLayerPropertiesForTesting(child.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(2, 2), gfx::Size(10, 10), true);
  
      scoped_refptr<NoScaleContentLayer> childNoScale = createNoScaleDrawableContentLayer(&delegate);
      setLayerPropertiesForTesting(childNoScale.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(2, 2), gfx::Size(10, 10), true);
  
      parent->addChild(child);
      parent->addChild(childNoScale);
  
      std::vector<scoped_refptr<Layer> > renderSurfaceLayerList;
      int dummyMaxTextureSize = 512;
  
      const double deviceScaleFactor = 2.5;
      const double pageScaleFactor = 1;
  
      LayerTreeHostCommon::calculateDrawTransforms(parent.get(), parent->bounds(), deviceScaleFactor, pageScaleFactor, dummyMaxTextureSize, renderSurfaceLayerList);
  
      EXPECT_CONTENTS_SCALE_EQ(deviceScaleFactor * pageScaleFactor, parent);
      EXPECT_CONTENTS_SCALE_EQ(deviceScaleFactor * pageScaleFactor, child);
      EXPECT_CONTENTS_SCALE_EQ(1, childNoScale);
  
      EXPECT_EQ(1u, renderSurfaceLayerList.size());
  
      // Verify parent transforms
      WebTransformationMatrix expectedParentTransform;
      EXPECT_TRANSFORMATION_MATRIX_EQ(expectedParentTransform, parent->screenSpaceTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(expectedParentTransform, parent->drawTransform());
  
      // Verify results of transformed parent rects
      gfx::RectF parentContentBounds(gfx::PointF(), gfx::SizeF(parent->contentBounds()));
  
      gfx::RectF parentDrawRect = MathUtil::mapClippedRect(parent->drawTransform(), parentContentBounds);
      gfx::RectF parentScreenSpaceRect = MathUtil::mapClippedRect(parent->screenSpaceTransform(), parentContentBounds);
  
      gfx::RectF expectedParentDrawRect(gfx::PointF(), parent->bounds());
      expectedParentDrawRect.Scale(deviceScaleFactor);
      EXPECT_FLOAT_RECT_EQ(expectedParentDrawRect, parentDrawRect);
      EXPECT_FLOAT_RECT_EQ(expectedParentDrawRect, parentScreenSpaceRect);
  
      // Verify child transforms
      WebTransformationMatrix expectedChildTransform;
      expectedChildTransform.translate(deviceScaleFactor * child->position().x(), deviceScaleFactor * child->position().y());
      EXPECT_TRANSFORMATION_MATRIX_EQ(expectedChildTransform, child->drawTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(expectedChildTransform, child->screenSpaceTransform());
  
      // Verify results of transformed child rects
      gfx::RectF childContentBounds(gfx::PointF(), gfx::SizeF(child->contentBounds()));
  
      gfx::RectF childDrawRect = MathUtil::mapClippedRect(child->drawTransform(), childContentBounds);
      gfx::RectF childScreenSpaceRect = MathUtil::mapClippedRect(child->screenSpaceTransform(), childContentBounds);
  
      gfx::RectF expectedChildDrawRect(gfx::PointF(), child->bounds());
      expectedChildDrawRect.Offset(child->position().x(), child->position().y());
      expectedChildDrawRect.Scale(deviceScaleFactor);
      EXPECT_FLOAT_RECT_EQ(expectedChildDrawRect, childDrawRect);
      EXPECT_FLOAT_RECT_EQ(expectedChildDrawRect, childScreenSpaceRect);
  
      // Verify childNoScale transforms
      WebTransformationMatrix expectedChildNoScaleTransform = child->drawTransform();
      // All transforms operate on content rects. The child's content rect
      // incorporates device scale, but the childNoScale does not; add it here.
      expectedChildNoScaleTransform.scale(deviceScaleFactor);
      EXPECT_TRANSFORMATION_MATRIX_EQ(expectedChildNoScaleTransform, childNoScale->drawTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(expectedChildNoScaleTransform, childNoScale->screenSpaceTransform());
  }
  
  TEST(LayerTreeHostCommonTest, verifyLayerTransformsInHighDPIAccurateScaleZeroChildPosition)
  {
      // Verify draw and screen space transforms of layers not in a surface.
      MockContentLayerClient delegate;
      WebTransformationMatrix identityMatrix;
  
      scoped_refptr<ContentLayer> parent = createDrawableContentLayer(&delegate);
      setLayerPropertiesForTesting(parent.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(133, 133), true);
  
      scoped_refptr<ContentLayer> child = createDrawableContentLayer(&delegate);
      setLayerPropertiesForTesting(child.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(13, 13), true);
  
      scoped_refptr<NoScaleContentLayer> childNoScale = createNoScaleDrawableContentLayer(&delegate);
      setLayerPropertiesForTesting(childNoScale.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(13, 13), true);
  
      parent->addChild(child);
      parent->addChild(childNoScale);
  
      std::vector<scoped_refptr<Layer> > renderSurfaceLayerList;
      int dummyMaxTextureSize = 512;
  
      const float deviceScaleFactor = 1.7f;
      const float pageScaleFactor = 1;
  
      LayerTreeHostCommon::calculateDrawTransforms(parent.get(), parent->bounds(), deviceScaleFactor, pageScaleFactor, dummyMaxTextureSize, renderSurfaceLayerList);
  
      EXPECT_CONTENTS_SCALE_EQ(deviceScaleFactor * pageScaleFactor, parent);
      EXPECT_CONTENTS_SCALE_EQ(deviceScaleFactor * pageScaleFactor, child);
      EXPECT_CONTENTS_SCALE_EQ(1, childNoScale);
  
      EXPECT_EQ(1u, renderSurfaceLayerList.size());
  
      // Verify parent transforms
      WebTransformationMatrix expectedParentTransform;
      EXPECT_TRANSFORMATION_MATRIX_EQ(expectedParentTransform, parent->screenSpaceTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(expectedParentTransform, parent->drawTransform());
  
      // Verify results of transformed parent rects
      gfx::RectF parentContentBounds(gfx::PointF(), gfx::SizeF(parent->contentBounds()));
  
      gfx::RectF parentDrawRect = MathUtil::mapClippedRect(parent->drawTransform(), parentContentBounds);
      gfx::RectF parentScreenSpaceRect = MathUtil::mapClippedRect(parent->screenSpaceTransform(), parentContentBounds);
  
      gfx::RectF expectedParentDrawRect(gfx::PointF(), parent->bounds());
      expectedParentDrawRect.Scale(deviceScaleFactor);
      expectedParentDrawRect.set_width(ceil(expectedParentDrawRect.width()));
      expectedParentDrawRect.set_height(ceil(expectedParentDrawRect.height()));
      EXPECT_FLOAT_RECT_EQ(expectedParentDrawRect, parentDrawRect);
      EXPECT_FLOAT_RECT_EQ(expectedParentDrawRect, parentScreenSpaceRect);
  
      // Verify child transforms
      WebTransformationMatrix expectedChildTransform;
      EXPECT_TRANSFORMATION_MATRIX_EQ(expectedChildTransform, child->drawTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(expectedChildTransform, child->screenSpaceTransform());
  
      // Verify results of transformed child rects
      gfx::RectF childContentBounds(gfx::PointF(), gfx::SizeF(child->contentBounds()));
  
      gfx::RectF childDrawRect = MathUtil::mapClippedRect(child->drawTransform(), childContentBounds);
      gfx::RectF childScreenSpaceRect = MathUtil::mapClippedRect(child->screenSpaceTransform(), childContentBounds);
  
      gfx::RectF expectedChildDrawRect(gfx::PointF(), child->bounds());
      expectedChildDrawRect.Scale(deviceScaleFactor);
      expectedChildDrawRect.set_width(ceil(expectedChildDrawRect.width()));
      expectedChildDrawRect.set_height(ceil(expectedChildDrawRect.height()));
      EXPECT_FLOAT_RECT_EQ(expectedChildDrawRect, childDrawRect);
      EXPECT_FLOAT_RECT_EQ(expectedChildDrawRect, childScreenSpaceRect);
  
      // Verify childNoScale transforms
      WebTransformationMatrix expectedChildNoScaleTransform = child->drawTransform();
      // All transforms operate on content rects. The child's content rect
      // incorporates device scale, but the childNoScale does not; add it here.
      expectedChildNoScaleTransform.scale(deviceScaleFactor);
      EXPECT_TRANSFORMATION_MATRIX_EQ(expectedChildNoScaleTransform, childNoScale->drawTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(expectedChildNoScaleTransform, childNoScale->screenSpaceTransform());
  }
  
  TEST(LayerTreeHostCommonTest, verifyContentsScale)
  {
      MockContentLayerClient delegate;
      WebTransformationMatrix identityMatrix;
  
      WebTransformationMatrix parentScaleMatrix;
      const double initialParentScale = 1.75;
      parentScaleMatrix.scale(initialParentScale);
  
      WebTransformationMatrix childScaleMatrix;
      const double initialChildScale = 1.25;
      childScaleMatrix.scale(initialChildScale);
  
      float fixedRasterScale = 2.5;
  
      scoped_refptr<ContentLayer> parent = createDrawableContentLayer(&delegate);
      setLayerPropertiesForTesting(parent.get(), parentScaleMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(100, 100), true);
  
      scoped_refptr<ContentLayer> childScale = createDrawableContentLayer(&delegate);
      setLayerPropertiesForTesting(childScale.get(), childScaleMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(2, 2), gfx::Size(10, 10), true);
  
      scoped_refptr<NoScaleContentLayer> childNoScale = createNoScaleDrawableContentLayer(&delegate);
      setLayerPropertiesForTesting(childNoScale.get(), childScaleMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(12, 12), gfx::Size(10, 10), true);
  
      scoped_refptr<ContentLayer> childNoAutoScale = createDrawableContentLayer(&delegate);
      setLayerPropertiesForTesting(childNoAutoScale.get(), childScaleMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(22, 22), gfx::Size(10, 10), true);
      childNoAutoScale->setAutomaticallyComputeRasterScale(false);
      childNoAutoScale->setRasterScale(fixedRasterScale);
  
      // FIXME: Remove this when pageScaleFactor is applied in the compositor.
      // Page scale should not apply to the parent.
      parent->setBoundsContainPageScale(true);
  
      parent->addChild(childScale);
      parent->addChild(childNoScale);
      parent->addChild(childNoAutoScale);
  
      std::vector<scoped_refptr<Layer> > renderSurfaceLayerList;
      int dummyMaxTextureSize = 512;
  
      double deviceScaleFactor = 2.5;
      double pageScaleFactor = 1.5;
  
      // FIXME: Remove this when pageScaleFactor is applied in the compositor.
      WebTransformationMatrix pageScaleMatrix;
      pageScaleMatrix.scale(pageScaleFactor);
      parent->setSublayerTransform(pageScaleMatrix);
  
      LayerTreeHostCommon::calculateDrawTransforms(parent.get(), parent->bounds(), deviceScaleFactor, pageScaleFactor, dummyMaxTextureSize, renderSurfaceLayerList);
  
      EXPECT_CONTENTS_SCALE_EQ(deviceScaleFactor * initialParentScale, parent);
      EXPECT_CONTENTS_SCALE_EQ(deviceScaleFactor * pageScaleFactor * initialParentScale * initialChildScale, childScale);
      EXPECT_CONTENTS_SCALE_EQ(1, childNoScale);
      EXPECT_CONTENTS_SCALE_EQ(deviceScaleFactor * pageScaleFactor * fixedRasterScale, childNoAutoScale);
  
      // The parent is scaled up and shouldn't need to scale during draw. The child that can scale its contents should
      // also not need to scale during draw. The other should.
      // There is some rounding error due to contentBounds being a rounded integer.
      EXPECT_NEAR(parent->drawTransform().m11(), 1, 0.01);
      EXPECT_NEAR(parent->drawTransform().m22(), 1, 0.01);
      EXPECT_NEAR(childScale->drawTransform().m11(), 1, 0.01);
      EXPECT_NEAR(childScale->drawTransform().m22(), 1, 0.01);
      EXPECT_FLOAT_EQ(deviceScaleFactor * pageScaleFactor * initialParentScale * initialChildScale, childNoScale->drawTransform().m11());
      EXPECT_FLOAT_EQ(deviceScaleFactor * pageScaleFactor * initialParentScale * initialChildScale, childNoScale->drawTransform().m22());
      EXPECT_NEAR(childNoAutoScale->drawTransform().m11(), initialParentScale * initialChildScale / fixedRasterScale, 0.01);
      EXPECT_NEAR(childNoAutoScale->drawTransform().m22(), initialParentScale * initialChildScale / fixedRasterScale, 0.01);
  
      // If the transform changes, we expect the contentsScale to remain unchanged.
      childScale->setTransform(identityMatrix);
  
      renderSurfaceLayerList.clear();
      LayerTreeHostCommon::calculateDrawTransforms(parent.get(), parent->bounds(), deviceScaleFactor, pageScaleFactor, dummyMaxTextureSize, renderSurfaceLayerList);
  
      EXPECT_CONTENTS_SCALE_EQ(deviceScaleFactor * initialParentScale, parent);
      EXPECT_CONTENTS_SCALE_EQ(deviceScaleFactor * pageScaleFactor * initialParentScale * initialChildScale, childScale);
      EXPECT_CONTENTS_SCALE_EQ(1, childNoScale);
  
      // But if the deviceScaleFactor or pageScaleFactor changes, then it should be updated, but using the initial transform.
      deviceScaleFactor = 2.25;
      pageScaleFactor = 1.25;
  
      // FIXME: Remove this when pageScaleFactor is applied in the compositor.
      pageScaleMatrix = identityMatrix;
      pageScaleMatrix.scale(pageScaleFactor);
      parent->setSublayerTransform(pageScaleMatrix);
  
      renderSurfaceLayerList.clear();
      LayerTreeHostCommon::calculateDrawTransforms(parent.get(), parent->bounds(), deviceScaleFactor, pageScaleFactor, dummyMaxTextureSize, renderSurfaceLayerList);
  
      EXPECT_CONTENTS_SCALE_EQ(deviceScaleFactor * initialParentScale, parent);
      EXPECT_CONTENTS_SCALE_EQ(deviceScaleFactor * pageScaleFactor * initialParentScale * initialChildScale, childScale);
      EXPECT_CONTENTS_SCALE_EQ(1, childNoScale);
      EXPECT_CONTENTS_SCALE_EQ(deviceScaleFactor * pageScaleFactor * fixedRasterScale, childNoAutoScale);
  }
  
  TEST(LayerTreeHostCommonTest, verifyContentsScaleForSurfaces)
  {
      MockContentLayerClient delegate;
      WebTransformationMatrix identityMatrix;
  
      WebTransformationMatrix parentScaleMatrix;
      const double initialParentScale = 2;
      parentScaleMatrix.scale(initialParentScale);
  
      WebTransformationMatrix childScaleMatrix;
      const double initialChildScale = 3;
      childScaleMatrix.scale(initialChildScale);
  
      float fixedRasterScale = 4;
  
      scoped_refptr<ContentLayer> parent = createDrawableContentLayer(&delegate);
      setLayerPropertiesForTesting(parent.get(), parentScaleMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(100, 100), true);
  
      scoped_refptr<ContentLayer> surfaceScale = createDrawableContentLayer(&delegate);
      setLayerPropertiesForTesting(surfaceScale.get(), childScaleMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(2, 2), gfx::Size(10, 10), true);
  
      scoped_refptr<ContentLayer> surfaceScaleChildScale = createDrawableContentLayer(&delegate);
      setLayerPropertiesForTesting(surfaceScaleChildScale.get(), childScaleMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(10, 10), true);
  
      scoped_refptr<NoScaleContentLayer> surfaceScaleChildNoScale = createNoScaleDrawableContentLayer(&delegate);
      setLayerPropertiesForTesting(surfaceScaleChildNoScale.get(), childScaleMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(10, 10), true);
  
      scoped_refptr<NoScaleContentLayer> surfaceNoScale = createNoScaleDrawableContentLayer(&delegate);
      setLayerPropertiesForTesting(surfaceNoScale.get(), childScaleMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(12, 12), gfx::Size(10, 10), true);
  
      scoped_refptr<ContentLayer> surfaceNoScaleChildScale = createDrawableContentLayer(&delegate);
      setLayerPropertiesForTesting(surfaceNoScaleChildScale.get(), childScaleMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(10, 10), true);
  
      scoped_refptr<NoScaleContentLayer> surfaceNoScaleChildNoScale = createNoScaleDrawableContentLayer(&delegate);
      setLayerPropertiesForTesting(surfaceNoScaleChildNoScale.get(), childScaleMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(10, 10), true);
  
      scoped_refptr<ContentLayer> surfaceNoAutoScale = createDrawableContentLayer(&delegate);
      setLayerPropertiesForTesting(surfaceNoAutoScale.get(), childScaleMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(22, 22), gfx::Size(10, 10), true);
      surfaceNoAutoScale->setAutomaticallyComputeRasterScale(false);
      surfaceNoAutoScale->setRasterScale(fixedRasterScale);
  
      scoped_refptr<ContentLayer> surfaceNoAutoScaleChildScale = createDrawableContentLayer(&delegate);
      setLayerPropertiesForTesting(surfaceNoAutoScaleChildScale.get(), childScaleMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(10, 10), true);
  
      scoped_refptr<NoScaleContentLayer> surfaceNoAutoScaleChildNoScale = createNoScaleDrawableContentLayer(&delegate);
      setLayerPropertiesForTesting(surfaceNoAutoScaleChildNoScale.get(), childScaleMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(10, 10), true);
  
      // FIXME: Remove this when pageScaleFactor is applied in the compositor.
      // Page scale should not apply to the parent.
      parent->setBoundsContainPageScale(true);
  
      parent->addChild(surfaceScale);
      parent->addChild(surfaceNoScale);
      parent->addChild(surfaceNoAutoScale);
  
      surfaceScale->setForceRenderSurface(true);
      surfaceScale->addChild(surfaceScaleChildScale);
      surfaceScale->addChild(surfaceScaleChildNoScale);
  
      surfaceNoScale->setForceRenderSurface(true);
      surfaceNoScale->addChild(surfaceNoScaleChildScale);
      surfaceNoScale->addChild(surfaceNoScaleChildNoScale);
  
      surfaceNoAutoScale->setForceRenderSurface(true);
      surfaceNoAutoScale->addChild(surfaceNoAutoScaleChildScale);
      surfaceNoAutoScale->addChild(surfaceNoAutoScaleChildNoScale);
  
      std::vector<scoped_refptr<Layer> > renderSurfaceLayerList;
      int dummyMaxTextureSize = 512;
  
      double deviceScaleFactor = 5;
      double pageScaleFactor = 7;
  
      // FIXME: Remove this when pageScaleFactor is applied in the compositor.
      WebTransformationMatrix pageScaleMatrix;
      pageScaleMatrix.scale(pageScaleFactor);
      parent->setSublayerTransform(pageScaleMatrix);
  
      LayerTreeHostCommon::calculateDrawTransforms(parent.get(), parent->bounds(), deviceScaleFactor, pageScaleFactor, dummyMaxTextureSize, renderSurfaceLayerList);
  
      EXPECT_CONTENTS_SCALE_EQ(deviceScaleFactor * initialParentScale, parent);
      EXPECT_CONTENTS_SCALE_EQ(deviceScaleFactor * pageScaleFactor * initialParentScale * initialChildScale, surfaceScale);
      EXPECT_CONTENTS_SCALE_EQ(1, surfaceNoScale);
      EXPECT_CONTENTS_SCALE_EQ(deviceScaleFactor * pageScaleFactor * fixedRasterScale, surfaceNoAutoScale);
  
      EXPECT_CONTENTS_SCALE_EQ(deviceScaleFactor * pageScaleFactor * initialParentScale * initialChildScale * initialChildScale, surfaceScaleChildScale);
      EXPECT_CONTENTS_SCALE_EQ(1, surfaceScaleChildNoScale);
      EXPECT_CONTENTS_SCALE_EQ(deviceScaleFactor * pageScaleFactor * initialParentScale * initialChildScale * initialChildScale, surfaceNoScaleChildScale);
      EXPECT_CONTENTS_SCALE_EQ(1, surfaceNoScaleChildNoScale);
      EXPECT_CONTENTS_SCALE_EQ(deviceScaleFactor * pageScaleFactor * initialParentScale * initialChildScale * initialChildScale, surfaceNoAutoScaleChildScale);
      EXPECT_CONTENTS_SCALE_EQ(1, surfaceNoAutoScaleChildNoScale);
  
      // The parent is scaled up and shouldn't need to scale during draw.
      EXPECT_FLOAT_EQ(1, parent->drawTransform().m11());
      EXPECT_FLOAT_EQ(1, parent->drawTransform().m22());
  
      // RenderSurfaces should always be 1:1 with their target.
      EXPECT_FLOAT_EQ(1, surfaceScale->renderSurface()->drawTransform().m11());
      EXPECT_FLOAT_EQ(1, surfaceScale->renderSurface()->drawTransform().m22());
  
      // The surfaceScale can apply contents scale so the layer shouldn't need to scale during draw.
      EXPECT_FLOAT_EQ(1, surfaceScale->drawTransform().m11());
      EXPECT_FLOAT_EQ(1, surfaceScale->drawTransform().m22());
  
      // The surfaceScaleChildScale can apply contents scale so it shouldn't need to scale during draw.
      EXPECT_FLOAT_EQ(1, surfaceScaleChildScale->drawTransform().m11());
      EXPECT_FLOAT_EQ(1, surfaceScaleChildScale->drawTransform().m22());
  
      // The surfaceScaleChildNoScale can not apply contents scale, so it needs to be scaled during draw.
      EXPECT_FLOAT_EQ(deviceScaleFactor * pageScaleFactor * initialParentScale * initialChildScale * initialChildScale, surfaceScaleChildNoScale->drawTransform().m11());
      EXPECT_FLOAT_EQ(deviceScaleFactor * pageScaleFactor * initialParentScale * initialChildScale * initialChildScale, surfaceScaleChildNoScale->drawTransform().m22());
  
      // RenderSurfaces should always be 1:1 with their target.
      EXPECT_FLOAT_EQ(1, surfaceNoScale->renderSurface()->drawTransform().m11());
      EXPECT_FLOAT_EQ(1, surfaceNoScale->renderSurface()->drawTransform().m22());
  
      // The surfaceNoScale layer can not apply contents scale, so it needs to be scaled during draw.
      EXPECT_FLOAT_EQ(deviceScaleFactor * pageScaleFactor * initialParentScale * initialChildScale, surfaceNoScale->drawTransform().m11());
      EXPECT_FLOAT_EQ(deviceScaleFactor * pageScaleFactor * initialParentScale * initialChildScale, surfaceNoScale->drawTransform().m22());
  
      // The surfaceScaleChildScale can apply contents scale so it shouldn't need to scale during draw.
      EXPECT_FLOAT_EQ(1, surfaceNoScaleChildScale->drawTransform().m11());
      EXPECT_FLOAT_EQ(1, surfaceNoScaleChildScale->drawTransform().m22());
  
      // The surfaceScaleChildNoScale can not apply contents scale, so it needs to be scaled during draw.
      EXPECT_FLOAT_EQ(deviceScaleFactor * pageScaleFactor * initialParentScale * initialChildScale * initialChildScale, surfaceNoScaleChildNoScale->drawTransform().m11());
      EXPECT_FLOAT_EQ(deviceScaleFactor * pageScaleFactor * initialParentScale * initialChildScale * initialChildScale, surfaceNoScaleChildNoScale->drawTransform().m22());
  
      // RenderSurfaces should always be 1:1 with their target.
      EXPECT_FLOAT_EQ(1, surfaceNoAutoScale->renderSurface()->drawTransform().m11());
      EXPECT_FLOAT_EQ(1, surfaceNoAutoScale->renderSurface()->drawTransform().m22());
  
      // The surfaceNoAutoScale layer has a fixed contents scale, so it needs to be scaled during draw.
      EXPECT_FLOAT_EQ(deviceScaleFactor * pageScaleFactor * initialParentScale * initialChildScale / (deviceScaleFactor * pageScaleFactor * fixedRasterScale), surfaceNoAutoScale->drawTransform().m11());
      EXPECT_FLOAT_EQ(deviceScaleFactor * pageScaleFactor * initialParentScale * initialChildScale / (deviceScaleFactor * pageScaleFactor * fixedRasterScale), surfaceNoAutoScale->drawTransform().m22());
  
      // The surfaceScaleChildScale can apply contents scale so it shouldn't need to scale during draw.
      EXPECT_FLOAT_EQ(1, surfaceNoAutoScaleChildScale->drawTransform().m11());
      EXPECT_FLOAT_EQ(1, surfaceNoAutoScaleChildScale->drawTransform().m22());
  
      // The surfaceScaleChildNoScale can not apply contents scale, so it needs to be scaled during draw.
      EXPECT_FLOAT_EQ(deviceScaleFactor * pageScaleFactor * initialParentScale * initialChildScale * initialChildScale, surfaceNoAutoScaleChildNoScale->drawTransform().m11());
      EXPECT_FLOAT_EQ(deviceScaleFactor * pageScaleFactor * initialParentScale * initialChildScale * initialChildScale, surfaceNoAutoScaleChildNoScale->drawTransform().m22());
  }
  
  TEST(LayerTreeHostCommonTest, verifyRenderSurfaceTransformsInHighDPI)
  {
      MockContentLayerClient delegate;
      WebTransformationMatrix identityMatrix;
  
      scoped_refptr<ContentLayer> parent = createDrawableContentLayer(&delegate);
      setLayerPropertiesForTesting(parent.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(30, 30), true);
  
      scoped_refptr<ContentLayer> child = createDrawableContentLayer(&delegate);
      setLayerPropertiesForTesting(child.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(2, 2), gfx::Size(10, 10), true);
  
      WebTransformationMatrix replicaTransform;
      replicaTransform.scaleNonUniform(1, -1);
      scoped_refptr<ContentLayer> replica = createDrawableContentLayer(&delegate);
      setLayerPropertiesForTesting(replica.get(), replicaTransform, identityMatrix, gfx::PointF(0, 0), gfx::PointF(2, 2), gfx::Size(10, 10), true);
  
      // This layer should end up in the same surface as child, with the same draw
      // and screen space transforms.
      scoped_refptr<ContentLayer> duplicateChildNonOwner = createDrawableContentLayer(&delegate);
      setLayerPropertiesForTesting(duplicateChildNonOwner.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(10, 10), true);
  
      parent->addChild(child);
      child->addChild(duplicateChildNonOwner);
      child->setReplicaLayer(replica.get());
  
      std::vector<scoped_refptr<Layer> > renderSurfaceLayerList;
      int dummyMaxTextureSize = 512;
  
      const double deviceScaleFactor = 1.5;
      parent->setContentsScale(deviceScaleFactor);
      child->setContentsScale(deviceScaleFactor);
      duplicateChildNonOwner->setContentsScale(deviceScaleFactor);
      replica->setContentsScale(deviceScaleFactor);
  
      LayerTreeHostCommon::calculateDrawTransforms(parent.get(), parent->bounds(), deviceScaleFactor, 1, dummyMaxTextureSize, renderSurfaceLayerList);
  
      // We should have two render surfaces. The root's render surface and child's
      // render surface (it needs one because it has a replica layer).
      EXPECT_EQ(2u, renderSurfaceLayerList.size());
  
      WebTransformationMatrix expectedParentTransform;
      EXPECT_TRANSFORMATION_MATRIX_EQ(expectedParentTransform, parent->screenSpaceTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(expectedParentTransform, parent->drawTransform());
  
      WebTransformationMatrix expectedDrawTransform;
      EXPECT_TRANSFORMATION_MATRIX_EQ(expectedDrawTransform, child->drawTransform());
  
      WebTransformationMatrix expectedScreenSpaceTransform;
      expectedScreenSpaceTransform.translate(deviceScaleFactor * child->position().x(), deviceScaleFactor * child->position().y());
      EXPECT_TRANSFORMATION_MATRIX_EQ(expectedScreenSpaceTransform, child->screenSpaceTransform());
  
      WebTransformationMatrix expectedDuplicateChildDrawTransform = child->drawTransform();
      EXPECT_TRANSFORMATION_MATRIX_EQ(child->drawTransform(), duplicateChildNonOwner->drawTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(child->screenSpaceTransform(), duplicateChildNonOwner->screenSpaceTransform());
      EXPECT_RECT_EQ(child->drawableContentRect(), duplicateChildNonOwner->drawableContentRect());
      EXPECT_EQ(child->contentBounds(), duplicateChildNonOwner->contentBounds());
  
      WebTransformationMatrix expectedRenderSurfaceDrawTransform;
      expectedRenderSurfaceDrawTransform.translate(deviceScaleFactor * child->position().x(), deviceScaleFactor * child->position().y());
      EXPECT_TRANSFORMATION_MATRIX_EQ(expectedRenderSurfaceDrawTransform, child->renderSurface()->drawTransform());
  
      WebTransformationMatrix expectedSurfaceDrawTransform;
      expectedSurfaceDrawTransform.translate(deviceScaleFactor * 2, deviceScaleFactor * 2);
      EXPECT_TRANSFORMATION_MATRIX_EQ(expectedSurfaceDrawTransform, child->renderSurface()->drawTransform());
  
      WebTransformationMatrix expectedSurfaceScreenSpaceTransform;
      expectedSurfaceScreenSpaceTransform.translate(deviceScaleFactor * 2, deviceScaleFactor * 2);
      EXPECT_TRANSFORMATION_MATRIX_EQ(expectedSurfaceScreenSpaceTransform, child->renderSurface()->screenSpaceTransform());
  
      WebTransformationMatrix expectedReplicaDrawTransform;
      expectedReplicaDrawTransform.setM22(-1);
      expectedReplicaDrawTransform.setM41(6);
      expectedReplicaDrawTransform.setM42(6);
      EXPECT_TRANSFORMATION_MATRIX_EQ(expectedReplicaDrawTransform, child->renderSurface()->replicaDrawTransform());
  
      WebTransformationMatrix expectedReplicaScreenSpaceTransform;
      expectedReplicaScreenSpaceTransform.setM22(-1);
      expectedReplicaScreenSpaceTransform.setM41(6);
      expectedReplicaScreenSpaceTransform.setM42(6);
      EXPECT_TRANSFORMATION_MATRIX_EQ(expectedReplicaScreenSpaceTransform, child->renderSurface()->replicaScreenSpaceTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(expectedReplicaScreenSpaceTransform, child->renderSurface()->replicaScreenSpaceTransform());
  }
  
  TEST(LayerTreeHostCommonTest, verifyRenderSurfaceTransformsInHighDPIAccurateScaleZeroPosition)
  {
      MockContentLayerClient delegate;
      WebTransformationMatrix identityMatrix;
  
      scoped_refptr<ContentLayer> parent = createDrawableContentLayer(&delegate);
      setLayerPropertiesForTesting(parent.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(33, 31), true);
  
      scoped_refptr<ContentLayer> child = createDrawableContentLayer(&delegate);
      setLayerPropertiesForTesting(child.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(13, 11), true);
  
      WebTransformationMatrix replicaTransform;
      replicaTransform.scaleNonUniform(1, -1);
      scoped_refptr<ContentLayer> replica = createDrawableContentLayer(&delegate);
      setLayerPropertiesForTesting(replica.get(), replicaTransform, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(13, 11), true);
  
      // This layer should end up in the same surface as child, with the same draw
      // and screen space transforms.
      scoped_refptr<ContentLayer> duplicateChildNonOwner = createDrawableContentLayer(&delegate);
      setLayerPropertiesForTesting(duplicateChildNonOwner.get(), identityMatrix, identityMatrix, gfx::PointF(0, 0), gfx::PointF(0, 0), gfx::Size(13, 11), true);
  
      parent->addChild(child);
      child->addChild(duplicateChildNonOwner);
      child->setReplicaLayer(replica.get());
  
      std::vector<scoped_refptr<Layer> > renderSurfaceLayerList;
      int dummyMaxTextureSize = 512;
  
      const float deviceScaleFactor = 1.7f;
      parent->setContentsScale(deviceScaleFactor);
      child->setContentsScale(deviceScaleFactor);
      duplicateChildNonOwner->setContentsScale(deviceScaleFactor);
      replica->setContentsScale(deviceScaleFactor);
  
      LayerTreeHostCommon::calculateDrawTransforms(parent.get(), parent->bounds(), deviceScaleFactor, 1, dummyMaxTextureSize, renderSurfaceLayerList);
  
      // We should have two render surfaces. The root's render surface and child's
      // render surface (it needs one because it has a replica layer).
      EXPECT_EQ(2u, renderSurfaceLayerList.size());
  
      WebTransformationMatrix identityTransform;
  
      EXPECT_TRANSFORMATION_MATRIX_EQ(identityTransform, parent->screenSpaceTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(identityTransform, parent->drawTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(identityTransform, child->drawTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(identityTransform, child->screenSpaceTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(identityTransform, duplicateChildNonOwner->drawTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(identityTransform, duplicateChildNonOwner->screenSpaceTransform());
      EXPECT_RECT_EQ(child->drawableContentRect(), duplicateChildNonOwner->drawableContentRect());
      EXPECT_EQ(child->contentBounds(), duplicateChildNonOwner->contentBounds());
  
      EXPECT_TRANSFORMATION_MATRIX_EQ(identityTransform, child->renderSurface()->drawTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(identityTransform, child->renderSurface()->drawTransform());
      EXPECT_TRANSFORMATION_MATRIX_EQ(identityTransform, child->renderSurface()->screenSpaceTransform());
  
      WebTransformationMatrix expectedReplicaDrawTransform;
      expectedReplicaDrawTransform.setM22(-1);
      EXPECT_TRANSFORMATION_MATRIX_EQ(expectedReplicaDrawTransform, child->renderSurface()->replicaDrawTransform());
  
      WebTransformationMatrix expectedReplicaScreenSpaceTransform;
      expectedReplicaScreenSpaceTransform.setM22(-1);
      EXPECT_TRANSFORMATION_MATRIX_EQ(expectedReplicaScreenSpaceTransform, child->renderSurface()->replicaScreenSpaceTransform());
  }
  
  TEST(LayerTreeHostCommonTest, verifySubtreeSearch)
  {
      scoped_refptr<Layer> root = Layer::create();
      scoped_refptr<Layer> child = Layer::create();
      scoped_refptr<Layer> grandChild = Layer::create();
      scoped_refptr<Layer> maskLayer = Layer::create();
      scoped_refptr<Layer> replicaLayer = Layer::create();
  
      grandChild->setReplicaLayer(replicaLayer.get());
      child->addChild(grandChild.get());
      child->setMaskLayer(maskLayer.get());
      root->addChild(child.get());
  
      int nonexistentId = -1;
      EXPECT_EQ(root, LayerTreeHostCommon::findLayerInSubtree(root.get(), root->id()));
      EXPECT_EQ(child, LayerTreeHostCommon::findLayerInSubtree(root.get(), child->id()));
      EXPECT_EQ(grandChild, LayerTreeHostCommon::findLayerInSubtree(root.get(), grandChild->id()));
      EXPECT_EQ(maskLayer, LayerTreeHostCommon::findLayerInSubtree(root.get(), maskLayer->id()));
      EXPECT_EQ(replicaLayer, LayerTreeHostCommon::findLayerInSubtree(root.get(), replicaLayer->id()));
      EXPECT_EQ(0, LayerTreeHostCommon::findLayerInSubtree(root.get(), nonexistentId));
  }
  
  } // namespace
  