text: // Copyright 2014 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 "cc/trees/layer_tree_impl.h"
  
  #include "cc/layers/heads_up_display_layer_impl.h"
  #include "cc/layers/layer.h"
  #include "cc/test/fake_impl_proxy.h"
  #include "cc/test/fake_layer_tree_host_impl.h"
  #include "cc/test/fake_output_surface.h"
  #include "cc/test/geometry_test_utils.h"
  #include "cc/test/layer_tree_host_common_test.h"
  #include "cc/test/test_shared_bitmap_manager.h"
  #include "cc/trees/layer_tree_host_impl.h"
  #include "ui/gfx/size_conversions.h"
  
  namespace cc {
  namespace {
  
  class LayerTreeImplTest : public LayerTreeHostCommonTest {
   public:
    LayerTreeImplTest() {
      LayerTreeSettings settings;
      settings.layer_transforms_should_scale_layer_contents = true;
      host_impl_.reset(
          new FakeLayerTreeHostImpl(settings, &proxy_, &shared_bitmap_manager_));
      EXPECT_TRUE(host_impl_->InitializeRenderer(
          FakeOutputSurface::Create3d().PassAs<OutputSurface>()));
    }
  
    FakeLayerTreeHostImpl& host_impl() { return *host_impl_; }
  
    LayerImpl* root_layer() { return host_impl_->active_tree()->root_layer(); }
  
    const LayerImplList& RenderSurfaceLayerList() const {
      return host_impl_->active_tree()->RenderSurfaceLayerList();
    }
  
   private:
    TestSharedBitmapManager shared_bitmap_manager_;
    FakeImplProxy proxy_;
    scoped_ptr<FakeLayerTreeHostImpl> host_impl_;
  };
  
  TEST_F(LayerTreeImplTest, HitTestingForSingleLayer) {
    scoped_ptr<LayerImpl> root =
        LayerImpl::Create(host_impl().active_tree(), 12345);
  
    gfx::Transform identity_matrix;
    gfx::Point3F transform_origin;
    gfx::PointF position;
    gfx::Size bounds(100, 100);
    SetLayerPropertiesForTesting(root.get(),
                                 identity_matrix,
                                 transform_origin,
                                 position,
                                 bounds,
                                 true,
                                 false);
    root->SetDrawsContent(true);
  
    host_impl().SetViewportSize(root->bounds());
    host_impl().active_tree()->SetRootLayer(root.Pass());
    host_impl().active_tree()->UpdateDrawProperties();
  
    // Sanity check the scenario we just created.
    ASSERT_EQ(1u, RenderSurfaceLayerList().size());
    ASSERT_EQ(1u, root_layer()->render_surface()->layer_list().size());
  
    // Hit testing for a point outside the layer should return a null pointer.
    gfx::Point test_point(101, 101);
    LayerImpl* result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPoint(test_point);
    EXPECT_FALSE(result_layer);
  
    test_point = gfx::Point(-1, -1);
    result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPoint(test_point);
    EXPECT_FALSE(result_layer);
  
    // Hit testing for a point inside should return the root layer.
    test_point = gfx::Point(1, 1);
    result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPoint(test_point);
    ASSERT_TRUE(result_layer);
    EXPECT_EQ(12345, result_layer->id());
  
    test_point = gfx::Point(99, 99);
    result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPoint(test_point);
    ASSERT_TRUE(result_layer);
    EXPECT_EQ(12345, result_layer->id());
  }
  
  TEST_F(LayerTreeImplTest, HitTestingForSingleLayerAndHud) {
    scoped_ptr<LayerImpl> root =
        LayerImpl::Create(host_impl().active_tree(), 12345);
    scoped_ptr<HeadsUpDisplayLayerImpl> hud =
        HeadsUpDisplayLayerImpl::Create(host_impl().active_tree(), 11111);
  
    gfx::Transform identity_matrix;
    gfx::Point3F transform_origin;
    gfx::PointF position;
    gfx::Size bounds(100, 100);
    SetLayerPropertiesForTesting(root.get(),
                                 identity_matrix,
                                 transform_origin,
                                 position,
                                 bounds,
                                 true,
                                 false);
    root->SetDrawsContent(true);
  
    // Create hud and add it as a child of root.
    gfx::Size hud_bounds(200, 200);
    SetLayerPropertiesForTesting(hud.get(),
                                 identity_matrix,
                                 transform_origin,
                                 position,
                                 hud_bounds,
                                 true,
                                 false);
    hud->SetDrawsContent(true);
  
    host_impl().active_tree()->set_hud_layer(hud.get());
    root->AddChild(hud.PassAs<LayerImpl>());
  
    host_impl().SetViewportSize(hud_bounds);
    host_impl().active_tree()->SetRootLayer(root.Pass());
    host_impl().active_tree()->UpdateDrawProperties();
  
    // Sanity check the scenario we just created.
    ASSERT_EQ(1u, RenderSurfaceLayerList().size());
    ASSERT_EQ(2u, root_layer()->render_surface()->layer_list().size());
  
    // Hit testing for a point inside HUD, but outside root should return null
    gfx::Point test_point(101, 101);
    LayerImpl* result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPoint(test_point);
    EXPECT_FALSE(result_layer);
  
    test_point = gfx::Point(-1, -1);
    result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPoint(test_point);
    EXPECT_FALSE(result_layer);
  
    // Hit testing for a point inside should return the root layer, never the HUD
    // layer.
    test_point = gfx::Point(1, 1);
    result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPoint(test_point);
    ASSERT_TRUE(result_layer);
    EXPECT_EQ(12345, result_layer->id());
  
    test_point = gfx::Point(99, 99);
    result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPoint(test_point);
    ASSERT_TRUE(result_layer);
    EXPECT_EQ(12345, result_layer->id());
  }
  
  TEST_F(LayerTreeImplTest, HitTestingForUninvertibleTransform) {
    scoped_ptr<LayerImpl> root =
        LayerImpl::Create(host_impl().active_tree(), 12345);
  
    gfx::Transform uninvertible_transform;
    uninvertible_transform.matrix().set(0, 0, 0.0);
    uninvertible_transform.matrix().set(1, 1, 0.0);
    uninvertible_transform.matrix().set(2, 2, 0.0);
    uninvertible_transform.matrix().set(3, 3, 0.0);
    ASSERT_FALSE(uninvertible_transform.IsInvertible());
  
    gfx::Transform identity_matrix;
    gfx::Point3F transform_origin;
    gfx::PointF position;
    gfx::Size bounds(100, 100);
    SetLayerPropertiesForTesting(root.get(),
                                 uninvertible_transform,
                                 transform_origin,
                                 position,
                                 bounds,
                                 true,
                                 false);
    root->SetDrawsContent(true);
  
    host_impl().SetViewportSize(root->bounds());
    host_impl().active_tree()->SetRootLayer(root.Pass());
    host_impl().active_tree()->UpdateDrawProperties();
    // Sanity check the scenario we just created.
    ASSERT_EQ(1u, RenderSurfaceLayerList().size());
    ASSERT_EQ(1u, root_layer()->render_surface()->layer_list().size());
    ASSERT_FALSE(root_layer()->screen_space_transform().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 test_point(1, 1);
    LayerImpl* result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPoint(test_point);
    EXPECT_FALSE(result_layer);
  
    test_point = gfx::Point(10, 10);
    result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPoint(test_point);
    EXPECT_FALSE(result_layer);
  
    test_point = gfx::Point(10, 30);
    result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPoint(test_point);
    EXPECT_FALSE(result_layer);
  
    test_point = gfx::Point(50, 50);
    result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPoint(test_point);
    EXPECT_FALSE(result_layer);
  
    test_point = gfx::Point(67, 48);
    result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPoint(test_point);
    EXPECT_FALSE(result_layer);
  
    test_point = gfx::Point(99, 99);
    result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPoint(test_point);
    EXPECT_FALSE(result_layer);
  
    test_point = gfx::Point(-1, -1);
    result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPoint(test_point);
    EXPECT_FALSE(result_layer);
  }
  
  TEST_F(LayerTreeImplTest, HitTestingForSinglePositionedLayer) {
    scoped_ptr<LayerImpl> root =
        LayerImpl::Create(host_impl().active_tree(), 12345);
  
    gfx::Transform identity_matrix;
    gfx::Point3F transform_origin;
    // this layer is positioned, and hit testing should correctly know where the
    // layer is located.
    gfx::PointF position(50.f, 50.f);
    gfx::Size bounds(100, 100);
    SetLayerPropertiesForTesting(root.get(),
                                 identity_matrix,
                                 transform_origin,
                                 position,
                                 bounds,
                                 true,
                                 false);
    root->SetDrawsContent(true);
  
    host_impl().SetViewportSize(root->bounds());
    host_impl().active_tree()->SetRootLayer(root.Pass());
    host_impl().active_tree()->UpdateDrawProperties();
  
    // Sanity check the scenario we just created.
    ASSERT_EQ(1u, RenderSurfaceLayerList().size());
    ASSERT_EQ(1u, root_layer()->render_surface()->layer_list().size());
  
    // Hit testing for a point outside the layer should return a null pointer.
    gfx::Point test_point(49, 49);
    LayerImpl* result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPoint(test_point);
    EXPECT_FALSE(result_layer);
  
    // Even though the layer exists at (101, 101), it should not be visible there
    // since the root render surface would clamp it.
    test_point = gfx::Point(101, 101);
    result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPoint(test_point);
    EXPECT_FALSE(result_layer);
  
    // Hit testing for a point inside should return the root layer.
    test_point = gfx::Point(51, 51);
    result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPoint(test_point);
    ASSERT_TRUE(result_layer);
    EXPECT_EQ(12345, result_layer->id());
  
    test_point = gfx::Point(99, 99);
    result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPoint(test_point);
    ASSERT_TRUE(result_layer);
    EXPECT_EQ(12345, result_layer->id());
  }
  
  TEST_F(LayerTreeImplTest, HitTestingForSingleRotatedLayer) {
    scoped_ptr<LayerImpl> root =
        LayerImpl::Create(host_impl().active_tree(), 12345);
  
    gfx::Transform identity_matrix;
    gfx::Transform rotation45_degrees_about_center;
    rotation45_degrees_about_center.Translate(50.0, 50.0);
    rotation45_degrees_about_center.RotateAboutZAxis(45.0);
    rotation45_degrees_about_center.Translate(-50.0, -50.0);
    gfx::Point3F transform_origin;
    gfx::PointF position;
    gfx::Size bounds(100, 100);
    SetLayerPropertiesForTesting(root.get(),
                                 rotation45_degrees_about_center,
                                 transform_origin,
                                 position,
                                 bounds,
                                 true,
                                 false);
    root->SetDrawsContent(true);
  
    host_impl().SetViewportSize(root->bounds());
    host_impl().active_tree()->SetRootLayer(root.Pass());
    host_impl().active_tree()->UpdateDrawProperties();
  
    // Sanity check the scenario we just created.
    ASSERT_EQ(1u, RenderSurfaceLayerList().size());
    ASSERT_EQ(1u, root_layer()->render_surface()->layer_list().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 test_point(99, 99);
    LayerImpl* result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPoint(test_point);
    EXPECT_FALSE(result_layer);
  
    test_point = gfx::Point(1, 1);
    result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPoint(test_point);
    EXPECT_FALSE(result_layer);
  
    // Hit testing for a point inside should return the root layer.
    test_point = gfx::Point(1, 50);
    result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPoint(test_point);
    ASSERT_TRUE(result_layer);
    EXPECT_EQ(12345, result_layer->id());
  
    // Hit testing the corners that would overlap the unclipped layer, but are
    // outside the clipped region.
    test_point = gfx::Point(50, -1);
    result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPoint(test_point);
    ASSERT_FALSE(result_layer);
  
    test_point = gfx::Point(-1, 50);
    result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPoint(test_point);
    ASSERT_FALSE(result_layer);
  }
  
  TEST_F(LayerTreeImplTest, HitTestingForSinglePerspectiveLayer) {
    scoped_ptr<LayerImpl> root =
        LayerImpl::Create(host_impl().active_tree(), 12345);
  
    gfx::Transform identity_matrix;
  
    // perspective_projection_about_center * translation_by_z is designed so that
    // the 100 x 100 layer becomes 50 x 50, and remains centered at (50, 50).
    gfx::Transform perspective_projection_about_center;
    perspective_projection_about_center.Translate(50.0, 50.0);
    perspective_projection_about_center.ApplyPerspectiveDepth(1.0);
    perspective_projection_about_center.Translate(-50.0, -50.0);
    gfx::Transform translation_by_z;
    translation_by_z.Translate3d(0.0, 0.0, -1.0);
  
    gfx::Point3F transform_origin;
    gfx::PointF position;
    gfx::Size bounds(100, 100);
    SetLayerPropertiesForTesting(
        root.get(),
        perspective_projection_about_center * translation_by_z,
        transform_origin,
        position,
        bounds,
        true,
        false);
    root->SetDrawsContent(true);
  
    host_impl().SetViewportSize(root->bounds());
    host_impl().active_tree()->SetRootLayer(root.Pass());
    host_impl().active_tree()->UpdateDrawProperties();
  
    // Sanity check the scenario we just created.
    ASSERT_EQ(1u, RenderSurfaceLayerList().size());
    ASSERT_EQ(1u, root_layer()->render_surface()->layer_list().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 test_point(24, 24);
    LayerImpl* result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPoint(test_point);
    EXPECT_FALSE(result_layer);
  
    test_point = gfx::Point(76, 76);
    result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPoint(test_point);
    EXPECT_FALSE(result_layer);
  
    // Hit testing for a point inside should return the root layer.
    test_point = gfx::Point(26, 26);
    result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPoint(test_point);
    ASSERT_TRUE(result_layer);
    EXPECT_EQ(12345, result_layer->id());
  
    test_point = gfx::Point(74, 74);
    result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPoint(test_point);
    ASSERT_TRUE(result_layer);
    EXPECT_EQ(12345, result_layer->id());
  }
  
  TEST_F(LayerTreeImplTest, HitTestingForSingleLayerWithScaledContents) {
    // A layer's visible content rect is actually in the layer's content space.
    // The screen space transform 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 contents scale 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
    // contents scale is ignored, then hit testing will mis-interpret the visible
    // content rect as being larger than the actual bounds of the layer.
    //
    scoped_ptr<LayerImpl> root = LayerImpl::Create(host_impl().active_tree(), 1);
  
    gfx::Transform identity_matrix;
    gfx::Point3F transform_origin;
  
    SetLayerPropertiesForTesting(root.get(),
                                 identity_matrix,
                                 transform_origin,
                                 gfx::PointF(),
                                 gfx::Size(100, 100),
                                 true,
                                 false);
    {
      gfx::PointF position(25.f, 25.f);
      gfx::Size bounds(50, 50);
      scoped_ptr<LayerImpl> test_layer =
          LayerImpl::Create(host_impl().active_tree(), 12345);
      SetLayerPropertiesForTesting(test_layer.get(),
                                   identity_matrix,
                                   transform_origin,
                                   position,
                                   bounds,
                                   true,
                                   false);
  
      // override content bounds and contents scale
      test_layer->SetContentBounds(gfx::Size(100, 100));
      test_layer->SetContentsScale(2, 2);
  
      test_layer->SetDrawsContent(true);
      root->AddChild(test_layer.Pass());
    }
  
    host_impl().SetViewportSize(root->bounds());
    host_impl().active_tree()->SetRootLayer(root.Pass());
    host_impl().active_tree()->UpdateDrawProperties();
  
    // Sanity check the scenario we just created.
    // The visible content rect for test_layer is actually 100x100, even though
    // its layout size is 50x50, positioned at 25x25.
    LayerImpl* test_layer =
        host_impl().active_tree()->root_layer()->children()[0];
    EXPECT_RECT_EQ(gfx::Rect(0, 0, 100, 100), test_layer->visible_content_rect());
    ASSERT_EQ(1u, RenderSurfaceLayerList().size());
    ASSERT_EQ(1u, root_layer()->render_surface()->layer_list().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 test_point(101, 101);
    LayerImpl* result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPoint(test_point);
    EXPECT_FALSE(result_layer);
  
    test_point = gfx::Point(24, 24);
    result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPoint(test_point);
    EXPECT_FALSE(result_layer);
  
    test_point = gfx::Point(76, 76);
    result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPoint(test_point);
    EXPECT_FALSE(result_layer);
  
    // Hit testing for a point inside should return the test layer.
    test_point = gfx::Point(26, 26);
    result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPoint(test_point);
    ASSERT_TRUE(result_layer);
    EXPECT_EQ(12345, result_layer->id());
  
    test_point = gfx::Point(74, 74);
    result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPoint(test_point);
    ASSERT_TRUE(result_layer);
    EXPECT_EQ(12345, result_layer->id());
  }
  
  TEST_F(LayerTreeImplTest, HitTestingForSimpleClippedLayer) {
    // 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.
    gfx::Transform identity_matrix;
    gfx::Point3F transform_origin;
  
    scoped_ptr<LayerImpl> root = LayerImpl::Create(host_impl().active_tree(), 1);
    SetLayerPropertiesForTesting(root.get(),
                                 identity_matrix,
                                 transform_origin,
                                 gfx::PointF(),
                                 gfx::Size(100, 100),
                                 true,
                                 false);
    {
      scoped_ptr<LayerImpl> clipping_layer =
          LayerImpl::Create(host_impl().active_tree(), 123);
      // this layer is positioned, and hit testing should correctly know where the
      // layer is located.
      gfx::PointF position(25.f, 25.f);
      gfx::Size bounds(50, 50);
      SetLayerPropertiesForTesting(clipping_layer.get(),
                                   identity_matrix,
                                   transform_origin,
                                   position,
                                   bounds,
                                   true,
                                   false);
      clipping_layer->SetMasksToBounds(true);
  
      scoped_ptr<LayerImpl> child =
          LayerImpl::Create(host_impl().active_tree(), 456);
      position = gfx::PointF(-50.f, -50.f);
      bounds = gfx::Size(300, 300);
      SetLayerPropertiesForTesting(child.get(),
                                   identity_matrix,
                                   transform_origin,
                                   position,
                                   bounds,
                                   true,
                                   false);
      child->SetDrawsContent(true);
      clipping_layer->AddChild(child.Pass());
      root->AddChild(clipping_layer.Pass());
    }
  
    host_impl().SetViewportSize(root->bounds());
    host_impl().active_tree()->SetRootLayer(root.Pass());
    host_impl().active_tree()->UpdateDrawProperties();
  
    // Sanity check the scenario we just created.
    ASSERT_EQ(1u, RenderSurfaceLayerList().size());
    ASSERT_EQ(1u, root_layer()->render_surface()->layer_list().size());
    ASSERT_EQ(456, root_layer()->render_surface()->layer_list().at(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 test_point(24, 24);
    LayerImpl* result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPoint(test_point);
    EXPECT_FALSE(result_layer);
  
    // Even though the layer exists at (101, 101), it should not be visible there
    // since the clipping_layer would clamp it.
    test_point = gfx::Point(76, 76);
    result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPoint(test_point);
    EXPECT_FALSE(result_layer);
  
    // Hit testing for a point inside should return the child layer.
    test_point = gfx::Point(26, 26);
    result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPoint(test_point);
    ASSERT_TRUE(result_layer);
    EXPECT_EQ(456, result_layer->id());
  
    test_point = gfx::Point(74, 74);
    result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPoint(test_point);
    ASSERT_TRUE(result_layer);
    EXPECT_EQ(456, result_layer->id());
  }
  
  TEST_F(LayerTreeImplTest, HitTestingForMultiClippedRotatedLayer) {
    // 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 grand_child layers are both initialized to clip the
    // rotated_leaf. The child layer is rotated about the top-left corner, so that
    // the root + child clips combined create a triangle. The rotated_leaf will
    // only be visible where it overlaps this triangle.
    //
    scoped_ptr<LayerImpl> root =
        LayerImpl::Create(host_impl().active_tree(), 123);
  
    gfx::Transform identity_matrix;
    gfx::Point3F transform_origin;
    gfx::PointF position;
    gfx::Size bounds(100, 100);
    SetLayerPropertiesForTesting(root.get(),
                                 identity_matrix,
                                 transform_origin,
                                 position,
                                 bounds,
                                 true,
                                 false);
    root->SetMasksToBounds(true);
    {
      scoped_ptr<LayerImpl> child =
          LayerImpl::Create(host_impl().active_tree(), 456);
      scoped_ptr<LayerImpl> grand_child =
          LayerImpl::Create(host_impl().active_tree(), 789);
      scoped_ptr<LayerImpl> rotated_leaf =
          LayerImpl::Create(host_impl().active_tree(), 2468);
  
      position = gfx::PointF(10.f, 10.f);
      bounds = gfx::Size(80, 80);
      SetLayerPropertiesForTesting(child.get(),
                                   identity_matrix,
                                   transform_origin,
                                   position,
                                   bounds,
                                   true,
                                   false);
      child->SetMasksToBounds(true);
  
      gfx::Transform rotation45_degrees_about_corner;
      rotation45_degrees_about_corner.RotateAboutZAxis(45.0);
  
      // remember, positioned with respect to its parent which is already at 10,
      // 10
      position = gfx::PointF();
      bounds =
          gfx::Size(200, 200);  // to ensure it covers at least sqrt(2) * 100.
      SetLayerPropertiesForTesting(grand_child.get(),
                                   rotation45_degrees_about_corner,
                                   transform_origin,
                                   position,
                                   bounds,
                                   true,
                                   false);
      grand_child->SetMasksToBounds(true);
  
      // Rotates about the center of the layer
      gfx::Transform rotated_leaf_transform;
      rotated_leaf_transform.Translate(
          -10.0, -10.0);  // cancel out the grand_parent's position
      rotated_leaf_transform.RotateAboutZAxis(
          -45.0);  // cancel out the corner 45-degree rotation of the parent.
      rotated_leaf_transform.Translate(50.0, 50.0);
      rotated_leaf_transform.RotateAboutZAxis(45.0);
      rotated_leaf_transform.Translate(-50.0, -50.0);
      position = gfx::PointF();
      bounds = gfx::Size(100, 100);
      SetLayerPropertiesForTesting(rotated_leaf.get(),
                                   rotated_leaf_transform,
                                   transform_origin,
                                   position,
                                   bounds,
                                   true,
                                   false);
      rotated_leaf->SetDrawsContent(true);
  
      grand_child->AddChild(rotated_leaf.Pass());
      child->AddChild(grand_child.Pass());
      root->AddChild(child.Pass());
    }
  
    host_impl().SetViewportSize(root->bounds());
    host_impl().active_tree()->SetRootLayer(root.Pass());
    host_impl().active_tree()->UpdateDrawProperties();
  
    // Sanity check the scenario we just created.
    // The grand_child is expected to create a render surface because it
    // MasksToBounds and is not axis aligned.
    ASSERT_EQ(2u, RenderSurfaceLayerList().size());
    ASSERT_EQ(
        1u,
        RenderSurfaceLayerList().at(0)->render_surface()->layer_list().size());
    ASSERT_EQ(789,
              RenderSurfaceLayerList()
                  .at(0)
                  ->render_surface()
                  ->layer_list()
                  .at(0)
                  ->id());  // grand_child's surface.
    ASSERT_EQ(
        1u,
        RenderSurfaceLayerList().at(1)->render_surface()->layer_list().size());
    ASSERT_EQ(
        2468,
        RenderSurfaceLayerList()[1]->render_surface()->layer_list().at(0)->id());
  
    // (11, 89) is close to the the bottom left corner within the clip, but it is
    // not inside the layer.
    gfx::Point test_point(11, 89);
    LayerImpl* result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPoint(test_point);
    EXPECT_FALSE(result_layer);
  
    // Closer inwards from the bottom left will overlap the layer.
    test_point = gfx::Point(25, 75);
    result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPoint(test_point);
    ASSERT_TRUE(result_layer);
    EXPECT_EQ(2468, result_layer->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 visible content rect without considering how parent may clip
    // the layer, then hit testing would accidentally think that the point
    // successfully hits the layer.
    test_point = gfx::Point(4, 50);
    result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPoint(test_point);
    EXPECT_FALSE(result_layer);
  
    // (11, 50) is inside the layer and within the clipped area.
    test_point = gfx::Point(11, 50);
    result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPoint(test_point);
    ASSERT_TRUE(result_layer);
    EXPECT_EQ(2468, result_layer->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.
    test_point = gfx::Point(51, 49);
    result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPoint(test_point);
    EXPECT_FALSE(result_layer);
  
    // Around the middle, just to the left and down, should successfully hit the
    // layer.
    test_point = gfx::Point(49, 51);
    result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPoint(test_point);
    ASSERT_TRUE(result_layer);
    EXPECT_EQ(2468, result_layer->id());
  }
  
  TEST_F(LayerTreeImplTest, HitTestingForNonClippingIntermediateLayer) {
    // This test checks that hit testing code does not accidentally clip to layer
    // bounds for a layer that actually does not clip.
    gfx::Transform identity_matrix;
    gfx::Point3F transform_origin;
  
    scoped_ptr<LayerImpl> root = LayerImpl::Create(host_impl().active_tree(), 1);
    SetLayerPropertiesForTesting(root.get(),
                                 identity_matrix,
                                 transform_origin,
                                 gfx::PointF(),
                                 gfx::Size(100, 100),
                                 true,
                                 false);
    {
      scoped_ptr<LayerImpl> intermediate_layer =
          LayerImpl::Create(host_impl().active_tree(), 123);
      // this layer is positioned, and hit testing should correctly know where the
      // layer is located.
      gfx::PointF position(10.f, 10.f);
      gfx::Size bounds(50, 50);
      SetLayerPropertiesForTesting(intermediate_layer.get(),
                                   identity_matrix,
                                   transform_origin,
                                   position,
                                   bounds,
                                   true,
                                   false);
      // Sanity check the intermediate layer should not clip.
      ASSERT_FALSE(intermediate_layer->masks_to_bounds());
      ASSERT_FALSE(intermediate_layer->mask_layer());
  
      // The child of the intermediate_layer is translated so that it does not
      // overlap intermediate_layer at all.  If child is incorrectly clipped, we
      // would not be able to hit it successfully.
      scoped_ptr<LayerImpl> child =
          LayerImpl::Create(host_impl().active_tree(), 456);
      position = gfx::PointF(60.f, 60.f);  // 70, 70 in screen space
      bounds = gfx::Size(20, 20);
      SetLayerPropertiesForTesting(child.get(),
                                   identity_matrix,
                                   transform_origin,
                                   position,
                                   bounds,
                                   true,
                                   false);
      child->SetDrawsContent(true);
      intermediate_layer->AddChild(child.Pass());
      root->AddChild(intermediate_layer.Pass());
    }
  
    host_impl().SetViewportSize(root->bounds());
    host_impl().active_tree()->SetRootLayer(root.Pass());
    host_impl().active_tree()->UpdateDrawProperties();
  
    // Sanity check the scenario we just created.
    ASSERT_EQ(1u, RenderSurfaceLayerList().size());
    ASSERT_EQ(1u, root_layer()->render_surface()->layer_list().size());
    ASSERT_EQ(456, root_layer()->render_surface()->layer_list().at(0)->id());
  
    // Hit testing for a point outside the layer should return a null pointer.
    gfx::Point test_point(69, 69);
    LayerImpl* result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPoint(test_point);
    EXPECT_FALSE(result_layer);
  
    test_point = gfx::Point(91, 91);
    result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPoint(test_point);
    EXPECT_FALSE(result_layer);
  
    // Hit testing for a point inside should return the child layer.
    test_point = gfx::Point(71, 71);
    result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPoint(test_point);
    ASSERT_TRUE(result_layer);
    EXPECT_EQ(456, result_layer->id());
  
    test_point = gfx::Point(89, 89);
    result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPoint(test_point);
    ASSERT_TRUE(result_layer);
    EXPECT_EQ(456, result_layer->id());
  }
  
  TEST_F(LayerTreeImplTest, HitTestingForMultipleLayers) {
    scoped_ptr<LayerImpl> root = LayerImpl::Create(host_impl().active_tree(), 1);
  
    gfx::Transform identity_matrix;
    gfx::Point3F transform_origin;
    gfx::PointF position;
    gfx::Size bounds(100, 100);
    SetLayerPropertiesForTesting(root.get(),
                                 identity_matrix,
                                 transform_origin,
                                 position,
                                 bounds,
                                 true,
                                 false);
    root->SetDrawsContent(true);
    {
      // child 1 and child2 are initialized to overlap between x=50 and x=60.
      // grand_child is set to overlap both child1 and child2 between y=50 and
      // y=60.  The expected stacking order is: (front) child2, (second)
      // grand_child, (third) child1, and (back) the root layer behind all other
      // layers.
  
      scoped_ptr<LayerImpl> child1 =
          LayerImpl::Create(host_impl().active_tree(), 2);
      scoped_ptr<LayerImpl> child2 =
          LayerImpl::Create(host_impl().active_tree(), 3);
      scoped_ptr<LayerImpl> grand_child1 =
          LayerImpl::Create(host_impl().active_tree(), 4);
  
      position = gfx::PointF(10.f, 10.f);
      bounds = gfx::Size(50, 50);
      SetLayerPropertiesForTesting(child1.get(),
                                   identity_matrix,
                                   transform_origin,
                                   position,
                                   bounds,
                                   true,
                                   false);
      child1->SetDrawsContent(true);
  
      position = gfx::PointF(50.f, 10.f);
      bounds = gfx::Size(50, 50);
      SetLayerPropertiesForTesting(child2.get(),
                                   identity_matrix,
                                   transform_origin,
                                   position,
                                   bounds,
                                   true,
                                   false);
      child2->SetDrawsContent(true);
  
      // Remember that grand_child 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.f, 40.f);
      bounds = gfx::Size(100, 50);
      SetLayerPropertiesForTesting(grand_child1.get(),
                                   identity_matrix,
                                   transform_origin,
                                   position,
                                   bounds,
                                   true,
                                   false);
      grand_child1->SetDrawsContent(true);
  
      child1->AddChild(grand_child1.Pass());
      root->AddChild(child1.Pass());
      root->AddChild(child2.Pass());
    }
  
    LayerImpl* child1 = root->children()[0];
    LayerImpl* child2 = root->children()[1];
    LayerImpl* grand_child1 = child1->children()[0];
  
    host_impl().SetViewportSize(root->bounds());
    host_impl().active_tree()->SetRootLayer(root.Pass());
    host_impl().active_tree()->UpdateDrawProperties();
  
    // Sanity check the scenario we just created.
    ASSERT_TRUE(child1);
    ASSERT_TRUE(child2);
    ASSERT_TRUE(grand_child1);
    ASSERT_EQ(1u, RenderSurfaceLayerList().size());
  
    RenderSurfaceImpl* root_render_surface = root_layer()->render_surface();
    ASSERT_EQ(4u, root_render_surface->layer_list().size());
    ASSERT_EQ(1, root_render_surface->layer_list().at(0)->id());  // root layer
    ASSERT_EQ(2, root_render_surface->layer_list().at(1)->id());  // child1
    ASSERT_EQ(4, root_render_surface->layer_list().at(2)->id());  // grand_child1
    ASSERT_EQ(3, root_render_surface->layer_list().at(3)->id());  // child2
  
    // Nothing overlaps the root_layer at (1, 1), so hit testing there should find
    // the root layer.
    gfx::Point test_point = gfx::Point(1, 1);
    LayerImpl* result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPoint(test_point);
    ASSERT_TRUE(result_layer);
    EXPECT_EQ(1, result_layer->id());
  
    // At (15, 15), child1 and root are the only layers. child1 is expected to be
    // on top.
    test_point = gfx::Point(15, 15);
    result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPoint(test_point);
    ASSERT_TRUE(result_layer);
    EXPECT_EQ(2, result_layer->id());
  
    // At (51, 20), child1 and child2 overlap. child2 is expected to be on top.
    test_point = gfx::Point(51, 20);
    result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPoint(test_point);
    ASSERT_TRUE(result_layer);
    EXPECT_EQ(3, result_layer->id());
  
    // At (80, 51), child2 and grand_child1 overlap. child2 is expected to be on
    // top.
    test_point = gfx::Point(80, 51);
    result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPoint(test_point);
    ASSERT_TRUE(result_layer);
    EXPECT_EQ(3, result_layer->id());
  
    // At (51, 51), all layers overlap each other. child2 is expected to be on top
    // of all other layers.
    test_point = gfx::Point(51, 51);
    result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPoint(test_point);
    ASSERT_TRUE(result_layer);
    EXPECT_EQ(3, result_layer->id());
  
    // At (20, 51), child1 and grand_child1 overlap. grand_child1 is expected to
    // be on top.
    test_point = gfx::Point(20, 51);
    result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPoint(test_point);
    ASSERT_TRUE(result_layer);
    EXPECT_EQ(4, result_layer->id());
  }
  
  TEST_F(LayerTreeImplTest, HitTestingForMultipleLayersAtVaryingDepths) {
    scoped_ptr<LayerImpl> root = LayerImpl::Create(host_impl().active_tree(), 1);
  
    gfx::Transform identity_matrix;
    gfx::Point3F transform_origin;
    gfx::PointF position;
    gfx::Size bounds(100, 100);
    SetLayerPropertiesForTesting(root.get(),
                                 identity_matrix,
                                 transform_origin,
                                 position,
                                 bounds,
                                 true,
                                 false);
    root->SetDrawsContent(true);
    root->SetShouldFlattenTransform(false);
    root->Set3dSortingContextId(1);
    {
      // child 1 and child2 are initialized to overlap between x=50 and x=60.
      // grand_child is set to overlap both child1 and child2 between y=50 and
      // y=60.  The expected stacking order is: (front) child2, (second)
      // grand_child, (third) child1, and (back) the root layer behind all other
      // layers.
  
      scoped_ptr<LayerImpl> child1 =
          LayerImpl::Create(host_impl().active_tree(), 2);
      scoped_ptr<LayerImpl> child2 =
          LayerImpl::Create(host_impl().active_tree(), 3);
      scoped_ptr<LayerImpl> grand_child1 =
          LayerImpl::Create(host_impl().active_tree(), 4);
  
      position = gfx::PointF(10.f, 10.f);
      bounds = gfx::Size(50, 50);
      SetLayerPropertiesForTesting(child1.get(),
                                   identity_matrix,
                                   transform_origin,
                                   position,
                                   bounds,
                                   true,
                                   false);
      child1->SetDrawsContent(true);
      child1->SetShouldFlattenTransform(false);
      child1->Set3dSortingContextId(1);
  
      position = gfx::PointF(50.f, 10.f);
      bounds = gfx::Size(50, 50);
      gfx::Transform translate_z;
      translate_z.Translate3d(0, 0, -10.f);
      SetLayerPropertiesForTesting(child2.get(),
                                   translate_z,
                                   transform_origin,
                                   position,
                                   bounds,
                                   true,
                                   false);
      child2->SetDrawsContent(true);
      child2->SetShouldFlattenTransform(false);
      child2->Set3dSortingContextId(1);
  
      // Remember that grand_child 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.f, 40.f);
      bounds = gfx::Size(100, 50);
      SetLayerPropertiesForTesting(grand_child1.get(),
                                   identity_matrix,
                                   transform_origin,
                                   position,
                                   bounds,
                                   true,
                                   false);
      grand_child1->SetDrawsContent(true);
      grand_child1->SetShouldFlattenTransform(false);
  
      child1->AddChild(grand_child1.Pass());
      root->AddChild(child1.Pass());
      root->AddChild(child2.Pass());
    }
  
    LayerImpl* child1 = root->children()[0];
    LayerImpl* child2 = root->children()[1];
    LayerImpl* grand_child1 = child1->children()[0];
  
    host_impl().SetViewportSize(root->bounds());
    host_impl().active_tree()->SetRootLayer(root.Pass());
    host_impl().active_tree()->UpdateDrawProperties();
  
    // Sanity check the scenario we just created.
    ASSERT_TRUE(child1);
    ASSERT_TRUE(child2);
    ASSERT_TRUE(grand_child1);
    ASSERT_EQ(1u, RenderSurfaceLayerList().size());
  
    RenderSurfaceImpl* root_render_surface =
        host_impl().active_tree()->root_layer()->render_surface();
    ASSERT_EQ(4u, root_render_surface->layer_list().size());
    ASSERT_EQ(3, root_render_surface->layer_list().at(0)->id());
    ASSERT_EQ(1, root_render_surface->layer_list().at(1)->id());
    ASSERT_EQ(2, root_render_surface->layer_list().at(2)->id());
    ASSERT_EQ(4, root_render_surface->layer_list().at(3)->id());
  
    // Nothing overlaps the root_layer at (1, 1), so hit testing there should find
    // the root layer.
    gfx::Point test_point = gfx::Point(1, 1);
    LayerImpl* result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPoint(test_point);
    ASSERT_TRUE(result_layer);
    EXPECT_EQ(1, result_layer->id());
  
    // At (15, 15), child1 and root are the only layers. child1 is expected to be
    // on top.
    test_point = gfx::Point(15, 15);
    result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPoint(test_point);
    ASSERT_TRUE(result_layer);
    EXPECT_EQ(2, result_layer->id());
  
    // At (51, 20), child1 and child2 overlap. child2 is expected to be on top.
    // (because 3 is transformed to the back).
    test_point = gfx::Point(51, 20);
    result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPoint(test_point);
    ASSERT_TRUE(result_layer);
    EXPECT_EQ(2, result_layer->id());
  
    // 3 Would have been on top if it hadn't been transformed to the background.
    // Make sure that it isn't hit.
    test_point = gfx::Point(80, 51);
    result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPoint(test_point);
    ASSERT_TRUE(result_layer);
    EXPECT_EQ(4, result_layer->id());
  
    // 3 Would have been on top if it hadn't been transformed to the background.
    // Make sure that it isn't hit.
    test_point = gfx::Point(51, 51);
    result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPoint(test_point);
    ASSERT_TRUE(result_layer);
    EXPECT_EQ(4, result_layer->id());
  
    // At (20, 51), child1 and grand_child1 overlap. grand_child1 is expected to
    // be on top.
    test_point = gfx::Point(20, 51);
    result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPoint(test_point);
    ASSERT_TRUE(result_layer);
    EXPECT_EQ(4, result_layer->id());
  }
  
  TEST_F(LayerTreeImplTest, HitTestingRespectsClipParents) {
    scoped_ptr<LayerImpl> root = LayerImpl::Create(host_impl().active_tree(), 1);
    gfx::Transform identity_matrix;
    gfx::Point3F transform_origin;
    gfx::PointF position;
    gfx::Size bounds(100, 100);
    SetLayerPropertiesForTesting(root.get(),
                                 identity_matrix,
                                 transform_origin,
                                 position,
                                 bounds,
                                 true,
                                 false);
    root->SetDrawsContent(true);
    {
      scoped_ptr<LayerImpl> child =
          LayerImpl::Create(host_impl().active_tree(), 2);
      scoped_ptr<LayerImpl> grand_child =
          LayerImpl::Create(host_impl().active_tree(), 4);
  
      position = gfx::PointF(10.f, 10.f);
      bounds = gfx::Size(1, 1);
      SetLayerPropertiesForTesting(child.get(),
                                   identity_matrix,
                                   transform_origin,
                                   position,
                                   bounds,
                                   true,
                                   false);
      child->SetDrawsContent(true);
      child->SetMasksToBounds(true);
  
      position = gfx::PointF(0.f, 40.f);
      bounds = gfx::Size(100, 50);
      SetLayerPropertiesForTesting(grand_child.get(),
                                   identity_matrix,
                                   transform_origin,
                                   position,
                                   bounds,
                                   true,
                                   false);
      grand_child->SetDrawsContent(true);
      grand_child->SetForceRenderSurface(true);
  
      // This should let |grand_child| "escape" |child|'s clip.
      grand_child->SetClipParent(root.get());
  
      child->AddChild(grand_child.Pass());
      root->AddChild(child.Pass());
    }
  
    host_impl().SetViewportSize(root->bounds());
    host_impl().active_tree()->SetRootLayer(root.Pass());
    host_impl().active_tree()->UpdateDrawProperties();
  
    gfx::Point test_point = gfx::Point(12, 52);
    LayerImpl* result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPoint(test_point);
    ASSERT_TRUE(result_layer);
    EXPECT_EQ(4, result_layer->id());
  }
  
  TEST_F(LayerTreeImplTest, HitTestingRespectsScrollParents) {
    scoped_ptr<LayerImpl> root = LayerImpl::Create(host_impl().active_tree(), 1);
    gfx::Transform identity_matrix;
    gfx::Point3F transform_origin;
    gfx::PointF position;
    gfx::Size bounds(100, 100);
    SetLayerPropertiesForTesting(root.get(),
                                 identity_matrix,
                                 transform_origin,
                                 position,
                                 bounds,
                                 true,
                                 false);
    root->SetDrawsContent(true);
    {
      scoped_ptr<LayerImpl> child =
          LayerImpl::Create(host_impl().active_tree(), 2);
      scoped_ptr<LayerImpl> scroll_child =
          LayerImpl::Create(host_impl().active_tree(), 3);
      scoped_ptr<LayerImpl> grand_child =
          LayerImpl::Create(host_impl().active_tree(), 4);
  
      position = gfx::PointF(10.f, 10.f);
      bounds = gfx::Size(1, 1);
      SetLayerPropertiesForTesting(child.get(),
                                   identity_matrix,
                                   transform_origin,
                                   position,
                                   bounds,
                                   true,
                                   false);
      child->SetDrawsContent(true);
      child->SetMasksToBounds(true);
  
      position = gfx::PointF();
      bounds = gfx::Size(200, 200);
      SetLayerPropertiesForTesting(scroll_child.get(),
                                   identity_matrix,
                                   transform_origin,
                                   position,
                                   bounds,
                                   true,
                                   false);
      scroll_child->SetDrawsContent(true);
  
      // This should cause scroll child and its descendants to be affected by
      // |child|'s clip.
      scroll_child->SetScrollParent(child.get());
  
      SetLayerPropertiesForTesting(grand_child.get(),
                                   identity_matrix,
                                   transform_origin,
                                   position,
                                   bounds,
                                   true,
                                   false);
      grand_child->SetDrawsContent(true);
      grand_child->SetForceRenderSurface(true);
  
      scroll_child->AddChild(grand_child.Pass());
      root->AddChild(scroll_child.Pass());
      root->AddChild(child.Pass());
    }
  
    host_impl().SetViewportSize(root->bounds());
    host_impl().active_tree()->SetRootLayer(root.Pass());
    host_impl().active_tree()->UpdateDrawProperties();
  
    gfx::Point test_point = gfx::Point(12, 52);
    LayerImpl* result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPoint(test_point);
    // The |test_point| should have been clipped away by |child|, the scroll
    // parent, so the only thing that should be hit is |root|.
    ASSERT_TRUE(result_layer);
    ASSERT_EQ(1, result_layer->id());
  }
  TEST_F(LayerTreeImplTest, HitTestingForMultipleLayerLists) {
    //
    // The geometry is set up similarly to the previous case, but
    // all layers are forced to be render surfaces now.
    //
    scoped_ptr<LayerImpl> root = LayerImpl::Create(host_impl().active_tree(), 1);
  
    gfx::Transform identity_matrix;
    gfx::Point3F transform_origin;
    gfx::PointF position;
    gfx::Size bounds(100, 100);
    SetLayerPropertiesForTesting(root.get(),
                                 identity_matrix,
                                 transform_origin,
                                 position,
                                 bounds,
                                 true,
                                 false);
    root->SetDrawsContent(true);
    {
      // child 1 and child2 are initialized to overlap between x=50 and x=60.
      // grand_child is set to overlap both child1 and child2 between y=50 and
      // y=60.  The expected stacking order is: (front) child2, (second)
      // grand_child, (third) child1, and (back) the root layer behind all other
      // layers.
  
      scoped_ptr<LayerImpl> child1 =
          LayerImpl::Create(host_impl().active_tree(), 2);
      scoped_ptr<LayerImpl> child2 =
          LayerImpl::Create(host_impl().active_tree(), 3);
      scoped_ptr<LayerImpl> grand_child1 =
          LayerImpl::Create(host_impl().active_tree(), 4);
  
      position = gfx::PointF(10.f, 10.f);
      bounds = gfx::Size(50, 50);
      SetLayerPropertiesForTesting(child1.get(),
                                   identity_matrix,
                                   transform_origin,
                                   position,
                                   bounds,
                                   true,
                                   false);
      child1->SetDrawsContent(true);
      child1->SetForceRenderSurface(true);
  
      position = gfx::PointF(50.f, 10.f);
      bounds = gfx::Size(50, 50);
      SetLayerPropertiesForTesting(child2.get(),
                                   identity_matrix,
                                   transform_origin,
                                   position,
                                   bounds,
                                   true,
                                   false);
      child2->SetDrawsContent(true);
      child2->SetForceRenderSurface(true);
  
      // Remember that grand_child 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.f, 40.f);
      bounds = gfx::Size(100, 50);
      SetLayerPropertiesForTesting(grand_child1.get(),
                                   identity_matrix,
                                   transform_origin,
                                   position,
                                   bounds,
                                   true,
                                   false);
      grand_child1->SetDrawsContent(true);
      grand_child1->SetForceRenderSurface(true);
  
      child1->AddChild(grand_child1.Pass());
      root->AddChild(child1.Pass());
      root->AddChild(child2.Pass());
    }
  
    LayerImpl* child1 = root->children()[0];
    LayerImpl* child2 = root->children()[1];
    LayerImpl* grand_child1 = child1->children()[0];
  
    host_impl().SetViewportSize(root->bounds());
    host_impl().active_tree()->SetRootLayer(root.Pass());
    host_impl().active_tree()->UpdateDrawProperties();
  
    // Sanity check the scenario we just created.
    ASSERT_TRUE(child1);
    ASSERT_TRUE(child2);
    ASSERT_TRUE(grand_child1);
    ASSERT_TRUE(child1->render_surface());
    ASSERT_TRUE(child2->render_surface());
    ASSERT_TRUE(grand_child1->render_surface());
    ASSERT_EQ(4u, RenderSurfaceLayerList().size());
    // The root surface has the root layer, and child1's and child2's render
    // surfaces.
    ASSERT_EQ(3u, root_layer()->render_surface()->layer_list().size());
    // The child1 surface has the child1 layer and grand_child1's render surface.
    ASSERT_EQ(2u, child1->render_surface()->layer_list().size());
    ASSERT_EQ(1u, child2->render_surface()->layer_list().size());
    ASSERT_EQ(1u, grand_child1->render_surface()->layer_list().size());
    ASSERT_EQ(1, RenderSurfaceLayerList().at(0)->id());  // root layer
    ASSERT_EQ(2, RenderSurfaceLayerList()[1]->id());     // child1
    ASSERT_EQ(4, RenderSurfaceLayerList().at(2)->id());  // grand_child1
    ASSERT_EQ(3, RenderSurfaceLayerList()[3]->id());     // child2
  
    // Nothing overlaps the root_layer at (1, 1), so hit testing there should find
    // the root layer.
    gfx::Point test_point = gfx::Point(1, 1);
    LayerImpl* result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPoint(test_point);
    ASSERT_TRUE(result_layer);
    EXPECT_EQ(1, result_layer->id());
  
    // At (15, 15), child1 and root are the only layers. child1 is expected to be
    // on top.
    test_point = gfx::Point(15, 15);
    result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPoint(test_point);
    ASSERT_TRUE(result_layer);
    EXPECT_EQ(2, result_layer->id());
  
    // At (51, 20), child1 and child2 overlap. child2 is expected to be on top.
    test_point = gfx::Point(51, 20);
    result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPoint(test_point);
    ASSERT_TRUE(result_layer);
    EXPECT_EQ(3, result_layer->id());
  
    // At (80, 51), child2 and grand_child1 overlap. child2 is expected to be on
    // top.
    test_point = gfx::Point(80, 51);
    result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPoint(test_point);
    ASSERT_TRUE(result_layer);
    EXPECT_EQ(3, result_layer->id());
  
    // At (51, 51), all layers overlap each other. child2 is expected to be on top
    // of all other layers.
    test_point = gfx::Point(51, 51);
    result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPoint(test_point);
    ASSERT_TRUE(result_layer);
    EXPECT_EQ(3, result_layer->id());
  
    // At (20, 51), child1 and grand_child1 overlap. grand_child1 is expected to
    // be on top.
    test_point = gfx::Point(20, 51);
    result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPoint(test_point);
    ASSERT_TRUE(result_layer);
    EXPECT_EQ(4, result_layer->id());
  }
  
  TEST_F(LayerTreeImplTest, HitCheckingTouchHandlerRegionsForSingleLayer) {
    scoped_ptr<LayerImpl> root =
        LayerImpl::Create(host_impl().active_tree(), 12345);
  
    gfx::Transform identity_matrix;
    Region touch_handler_region(gfx::Rect(10, 10, 50, 50));
    gfx::Point3F transform_origin;
    gfx::PointF position;
    gfx::Size bounds(100, 100);
    SetLayerPropertiesForTesting(root.get(),
                                 identity_matrix,
                                 transform_origin,
                                 position,
                                 bounds,
                                 true,
                                 false);
    root->SetDrawsContent(true);
  
    host_impl().SetViewportSize(root->bounds());
    host_impl().active_tree()->SetRootLayer(root.Pass());
    host_impl().active_tree()->UpdateDrawProperties();
  
    // Sanity check the scenario we just created.
    ASSERT_EQ(1u, RenderSurfaceLayerList().size());
    ASSERT_EQ(1u, root_layer()->render_surface()->layer_list().size());
  
    // Hit checking for any point should return a null pointer for a layer without
    // any touch event handler regions.
    gfx::Point test_point(11, 11);
    LayerImpl* result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPointInTouchHandlerRegion(
            test_point);
    EXPECT_FALSE(result_layer);
  
    host_impl().active_tree()->root_layer()->SetTouchEventHandlerRegion(
        touch_handler_region);
    // Hit checking for a point outside the layer should return a null pointer.
    test_point = gfx::Point(101, 101);
    result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPointInTouchHandlerRegion(
            test_point);
    EXPECT_FALSE(result_layer);
  
    test_point = gfx::Point(-1, -1);
    result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPointInTouchHandlerRegion(
            test_point);
    EXPECT_FALSE(result_layer);
  
    // Hit checking for a point inside the layer, but outside the touch handler
    // region should return a null pointer.
    test_point = gfx::Point(1, 1);
    result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPointInTouchHandlerRegion(
            test_point);
    EXPECT_FALSE(result_layer);
  
    test_point = gfx::Point(99, 99);
    result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPointInTouchHandlerRegion(
            test_point);
    EXPECT_FALSE(result_layer);
  
    // Hit checking for a point inside the touch event handler region should
    // return the root layer.
    test_point = gfx::Point(11, 11);
    result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPointInTouchHandlerRegion(
            test_point);
    ASSERT_TRUE(result_layer);
    EXPECT_EQ(12345, result_layer->id());
  
    test_point = gfx::Point(59, 59);
    result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPointInTouchHandlerRegion(
            test_point);
    ASSERT_TRUE(result_layer);
    EXPECT_EQ(12345, result_layer->id());
  }
  
  TEST_F(LayerTreeImplTest,
         HitCheckingTouchHandlerRegionsForUninvertibleTransform) {
    scoped_ptr<LayerImpl> root =
        LayerImpl::Create(host_impl().active_tree(), 12345);
  
    gfx::Transform uninvertible_transform;
    uninvertible_transform.matrix().set(0, 0, 0.0);
    uninvertible_transform.matrix().set(1, 1, 0.0);
    uninvertible_transform.matrix().set(2, 2, 0.0);
    uninvertible_transform.matrix().set(3, 3, 0.0);
    ASSERT_FALSE(uninvertible_transform.IsInvertible());
  
    gfx::Transform identity_matrix;
    Region touch_handler_region(gfx::Rect(10, 10, 50, 50));
    gfx::Point3F transform_origin;
    gfx::PointF position;
    gfx::Size bounds(100, 100);
    SetLayerPropertiesForTesting(root.get(),
                                 uninvertible_transform,
                                 transform_origin,
                                 position,
                                 bounds,
                                 true,
                                 false);
    root->SetDrawsContent(true);
    root->SetTouchEventHandlerRegion(touch_handler_region);
  
    host_impl().SetViewportSize(root->bounds());
    host_impl().active_tree()->SetRootLayer(root.Pass());
    host_impl().active_tree()->UpdateDrawProperties();
  
    // Sanity check the scenario we just created.
    ASSERT_EQ(1u, RenderSurfaceLayerList().size());
    ASSERT_EQ(1u, root_layer()->render_surface()->layer_list().size());
    ASSERT_FALSE(root_layer()->screen_space_transform().IsInvertible());
  
    // Hit checking any point should not hit the touch handler region on 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 test_point(1, 1);
    LayerImpl* result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPointInTouchHandlerRegion(
            test_point);
    EXPECT_FALSE(result_layer);
  
    test_point = gfx::Point(10, 10);
    result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPointInTouchHandlerRegion(
            test_point);
    EXPECT_FALSE(result_layer);
  
    test_point = gfx::Point(10, 30);
    result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPointInTouchHandlerRegion(
            test_point);
    EXPECT_FALSE(result_layer);
  
    test_point = gfx::Point(50, 50);
    result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPointInTouchHandlerRegion(
            test_point);
    EXPECT_FALSE(result_layer);
  
    test_point = gfx::Point(67, 48);
    result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPointInTouchHandlerRegion(
            test_point);
    EXPECT_FALSE(result_layer);
  
    test_point = gfx::Point(99, 99);
    result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPointInTouchHandlerRegion(
            test_point);
    EXPECT_FALSE(result_layer);
  
    test_point = gfx::Point(-1, -1);
    result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPointInTouchHandlerRegion(
            test_point);
    EXPECT_FALSE(result_layer);
  }
  
  TEST_F(LayerTreeImplTest,
         HitCheckingTouchHandlerRegionsForSinglePositionedLayer) {
    scoped_ptr<LayerImpl> root =
        LayerImpl::Create(host_impl().active_tree(), 12345);
  
    gfx::Transform identity_matrix;
    Region touch_handler_region(gfx::Rect(10, 10, 50, 50));
    gfx::Point3F transform_origin;
    // this layer is positioned, and hit testing should correctly know where the
    // layer is located.
    gfx::PointF position(50.f, 50.f);
    gfx::Size bounds(100, 100);
    SetLayerPropertiesForTesting(root.get(),
                                 identity_matrix,
                                 transform_origin,
                                 position,
                                 bounds,
                                 true,
                                 false);
    root->SetDrawsContent(true);
    root->SetTouchEventHandlerRegion(touch_handler_region);
  
    host_impl().SetViewportSize(root->bounds());
    host_impl().active_tree()->SetRootLayer(root.Pass());
    host_impl().active_tree()->UpdateDrawProperties();
  
    // Sanity check the scenario we just created.
    ASSERT_EQ(1u, RenderSurfaceLayerList().size());
    ASSERT_EQ(1u, root_layer()->render_surface()->layer_list().size());
  
    // Hit checking for a point outside the layer should return a null pointer.
    gfx::Point test_point(49, 49);
    LayerImpl* result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPointInTouchHandlerRegion(
            test_point);
    EXPECT_FALSE(result_layer);
  
    // Even though the layer has a touch handler region containing (101, 101), it
    // should not be visible there since the root render surface would clamp it.
    test_point = gfx::Point(101, 101);
    result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPointInTouchHandlerRegion(
            test_point);
    EXPECT_FALSE(result_layer);
  
    // Hit checking for a point inside the layer, but outside the touch handler
    // region should return a null pointer.
    test_point = gfx::Point(51, 51);
    result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPointInTouchHandlerRegion(
            test_point);
    EXPECT_FALSE(result_layer);
  
    // Hit checking for a point inside the touch event handler region should
    // return the root layer.
    test_point = gfx::Point(61, 61);
    result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPointInTouchHandlerRegion(
            test_point);
    ASSERT_TRUE(result_layer);
    EXPECT_EQ(12345, result_layer->id());
  
    test_point = gfx::Point(99, 99);
    result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPointInTouchHandlerRegion(
            test_point);
    ASSERT_TRUE(result_layer);
    EXPECT_EQ(12345, result_layer->id());
  }
  
  TEST_F(LayerTreeImplTest,
         HitCheckingTouchHandlerRegionsForSingleLayerWithScaledContents) {
    // A layer's visible content rect is actually in the layer's content space.
    // The screen space transform 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 contents scale 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
    // contents scale is ignored, then hit checking will mis-interpret the visible
    // content rect as being larger than the actual bounds of the layer.
    //
    scoped_ptr<LayerImpl> root = LayerImpl::Create(host_impl().active_tree(), 1);
  
    gfx::Transform identity_matrix;
    gfx::Point3F transform_origin;
  
    SetLayerPropertiesForTesting(root.get(),
                                 identity_matrix,
                                 transform_origin,
                                 gfx::PointF(),
                                 gfx::Size(100, 100),
                                 true,
                                 false);
    {
      Region touch_handler_region(gfx::Rect(10, 10, 30, 30));
      gfx::PointF position(25.f, 25.f);
      gfx::Size bounds(50, 50);
      scoped_ptr<LayerImpl> test_layer =
          LayerImpl::Create(host_impl().active_tree(), 12345);
      SetLayerPropertiesForTesting(test_layer.get(),
                                   identity_matrix,
                                   transform_origin,
                                   position,
                                   bounds,
                                   true,
                                   false);
  
      // override content bounds and contents scale
      test_layer->SetContentBounds(gfx::Size(100, 100));
      test_layer->SetContentsScale(2, 2);
  
      test_layer->SetDrawsContent(true);
      test_layer->SetTouchEventHandlerRegion(touch_handler_region);
      root->AddChild(test_layer.Pass());
    }
  
    host_impl().SetViewportSize(root->bounds());
    host_impl().active_tree()->SetRootLayer(root.Pass());
    host_impl().active_tree()->UpdateDrawProperties();
  
    // Sanity check the scenario we just created.
    // The visible content rect for test_layer is actually 100x100, even though
    // its layout size is 50x50, positioned at 25x25.
    LayerImpl* test_layer =
        host_impl().active_tree()->root_layer()->children()[0];
    EXPECT_RECT_EQ(gfx::Rect(0, 0, 100, 100), test_layer->visible_content_rect());
    ASSERT_EQ(1u, RenderSurfaceLayerList().size());
    ASSERT_EQ(1u, root_layer()->render_surface()->layer_list().size());
  
    // Hit checking for a point outside the layer should return a null pointer
    // (the root layer does not draw content, so it will not be tested either).
    gfx::Point test_point(76, 76);
    LayerImpl* result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPointInTouchHandlerRegion(
            test_point);
    EXPECT_FALSE(result_layer);
  
    // Hit checking for a point inside the layer, but outside the touch handler
    // region should return a null pointer.
    test_point = gfx::Point(26, 26);
    result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPointInTouchHandlerRegion(
            test_point);
    EXPECT_FALSE(result_layer);
  
    test_point = gfx::Point(34, 34);
    result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPointInTouchHandlerRegion(
            test_point);
    EXPECT_FALSE(result_layer);
  
    test_point = gfx::Point(65, 65);
    result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPointInTouchHandlerRegion(
            test_point);
    EXPECT_FALSE(result_layer);
  
    test_point = gfx::Point(74, 74);
    result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPointInTouchHandlerRegion(
            test_point);
    EXPECT_FALSE(result_layer);
  
    // Hit checking for a point inside the touch event handler region should
    // return the root layer.
    test_point = gfx::Point(35, 35);
    result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPointInTouchHandlerRegion(
            test_point);
    ASSERT_TRUE(result_layer);
    EXPECT_EQ(12345, result_layer->id());
  
    test_point = gfx::Point(64, 64);
    result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPointInTouchHandlerRegion(
            test_point);
    ASSERT_TRUE(result_layer);
    EXPECT_EQ(12345, result_layer->id());
  }
  
  TEST_F(LayerTreeImplTest,
         HitCheckingTouchHandlerRegionsForSingleLayerWithDeviceScale) {
    // The layer's device_scale_factor and page_scale_factor should scale the
    // content rect and we should be able to hit the touch handler region by
    // scaling the points accordingly.
    scoped_ptr<LayerImpl> root = LayerImpl::Create(host_impl().active_tree(), 1);
  
    gfx::Transform identity_matrix;
    gfx::Point3F transform_origin;
    // Set the bounds of the root layer big enough to fit the child when scaled.
    SetLayerPropertiesForTesting(root.get(),
                                 identity_matrix,
                                 transform_origin,
                                 gfx::PointF(),
                                 gfx::Size(100, 100),
                                 true,
                                 false);
    {
      Region touch_handler_region(gfx::Rect(10, 10, 30, 30));
      gfx::PointF position(25.f, 25.f);
      gfx::Size bounds(50, 50);
      scoped_ptr<LayerImpl> test_layer =
          LayerImpl::Create(host_impl().active_tree(), 12345);
      SetLayerPropertiesForTesting(test_layer.get(),
                                   identity_matrix,
                                   transform_origin,
                                   position,
                                   bounds,
                                   true,
                                   false);
  
      test_layer->SetDrawsContent(true);
      test_layer->SetTouchEventHandlerRegion(touch_handler_region);
      root->AddChild(test_layer.Pass());
    }
  
    float device_scale_factor = 3.f;
    float page_scale_factor = 5.f;
    gfx::Size scaled_bounds_for_root = gfx::ToCeiledSize(
        gfx::ScaleSize(root->bounds(), device_scale_factor * page_scale_factor));
    host_impl().SetViewportSize(scaled_bounds_for_root);
  
    host_impl().SetDeviceScaleFactor(device_scale_factor);
    host_impl().active_tree()->SetPageScaleFactorAndLimits(
        page_scale_factor, page_scale_factor, page_scale_factor);
    host_impl().active_tree()->SetRootLayer(root.Pass());
    host_impl().active_tree()->SetViewportLayersFromIds(1, 1, Layer::INVALID_ID);
    host_impl().active_tree()->UpdateDrawProperties();
  
    // Sanity check the scenario we just created.
    // The visible content rect for test_layer is actually 100x100, even though
    // its layout size is 50x50, positioned at 25x25.
    LayerImpl* test_layer =
        host_impl().active_tree()->root_layer()->children()[0];
    ASSERT_EQ(1u, RenderSurfaceLayerList().size());
    ASSERT_EQ(1u, root_layer()->render_surface()->layer_list().size());
  
    // Check whether the child layer fits into the root after scaled.
    EXPECT_RECT_EQ(gfx::Rect(test_layer->content_bounds()),
                   test_layer->visible_content_rect());
  
    // Hit checking for a point outside the layer should return a null pointer
    // (the root layer does not draw content, so it will not be tested either).
    gfx::PointF test_point(76.f, 76.f);
    test_point =
        gfx::ScalePoint(test_point, device_scale_factor * page_scale_factor);
    LayerImpl* result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPointInTouchHandlerRegion(
            test_point);
    EXPECT_FALSE(result_layer);
  
    // Hit checking for a point inside the layer, but outside the touch handler
    // region should return a null pointer.
    test_point = gfx::Point(26, 26);
    test_point =
        gfx::ScalePoint(test_point, device_scale_factor * page_scale_factor);
    result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPointInTouchHandlerRegion(
            test_point);
    EXPECT_FALSE(result_layer);
  
    test_point = gfx::Point(34, 34);
    test_point =
        gfx::ScalePoint(test_point, device_scale_factor * page_scale_factor);
    result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPointInTouchHandlerRegion(
            test_point);
    EXPECT_FALSE(result_layer);
  
    test_point = gfx::Point(65, 65);
    test_point =
        gfx::ScalePoint(test_point, device_scale_factor * page_scale_factor);
    result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPointInTouchHandlerRegion(
            test_point);
    EXPECT_FALSE(result_layer);
  
    test_point = gfx::Point(74, 74);
    test_point =
        gfx::ScalePoint(test_point, device_scale_factor * page_scale_factor);
    result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPointInTouchHandlerRegion(
            test_point);
    EXPECT_FALSE(result_layer);
  
    // Hit checking for a point inside the touch event handler region should
    // return the root layer.
    test_point = gfx::Point(35, 35);
    test_point =
        gfx::ScalePoint(test_point, device_scale_factor * page_scale_factor);
    result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPointInTouchHandlerRegion(
            test_point);
    ASSERT_TRUE(result_layer);
    EXPECT_EQ(12345, result_layer->id());
  
    test_point = gfx::Point(64, 64);
    test_point =
        gfx::ScalePoint(test_point, device_scale_factor * page_scale_factor);
    result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPointInTouchHandlerRegion(
            test_point);
    ASSERT_TRUE(result_layer);
    EXPECT_EQ(12345, result_layer->id());
  }
  
  TEST_F(LayerTreeImplTest, HitCheckingTouchHandlerRegionsForSimpleClippedLayer) {
    // Test that hit-checking 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.
    gfx::Transform identity_matrix;
    gfx::Point3F transform_origin;
  
    scoped_ptr<LayerImpl> root = LayerImpl::Create(host_impl().active_tree(), 1);
    SetLayerPropertiesForTesting(root.get(),
                                 identity_matrix,
                                 transform_origin,
                                 gfx::PointF(),
                                 gfx::Size(100, 100),
                                 true,
                                 false);
    {
      scoped_ptr<LayerImpl> clipping_layer =
          LayerImpl::Create(host_impl().active_tree(), 123);
      // this layer is positioned, and hit testing should correctly know where the
      // layer is located.
      gfx::PointF position(25.f, 25.f);
      gfx::Size bounds(50, 50);
      SetLayerPropertiesForTesting(clipping_layer.get(),
                                   identity_matrix,
                                   transform_origin,
                                   position,
                                   bounds,
                                   true,
                                   false);
      clipping_layer->SetMasksToBounds(true);
  
      scoped_ptr<LayerImpl> child =
          LayerImpl::Create(host_impl().active_tree(), 456);
      Region touch_handler_region(gfx::Rect(10, 10, 50, 50));
      position = gfx::PointF(-50.f, -50.f);
      bounds = gfx::Size(300, 300);
      SetLayerPropertiesForTesting(child.get(),
                                   identity_matrix,
                                   transform_origin,
                                   position,
                                   bounds,
                                   true,
                                   false);
      child->SetDrawsContent(true);
      child->SetTouchEventHandlerRegion(touch_handler_region);
      clipping_layer->AddChild(child.Pass());
      root->AddChild(clipping_layer.Pass());
    }
  
    host_impl().SetViewportSize(root->bounds());
    host_impl().active_tree()->SetRootLayer(root.Pass());
    host_impl().active_tree()->UpdateDrawProperties();
  
    // Sanity check the scenario we just created.
    ASSERT_EQ(1u, RenderSurfaceLayerList().size());
    ASSERT_EQ(1u, root_layer()->render_surface()->layer_list().size());
    ASSERT_EQ(456, root_layer()->render_surface()->layer_list().at(0)->id());
  
    // Hit checking 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 test_point(24, 24);
    LayerImpl* result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPointInTouchHandlerRegion(
            test_point);
    EXPECT_FALSE(result_layer);
  
    // Hit checking for a point inside the layer, but outside the touch handler
    // region should return a null pointer.
    test_point = gfx::Point(35, 35);
    result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPointInTouchHandlerRegion(
            test_point);
    EXPECT_FALSE(result_layer);
  
    test_point = gfx::Point(74, 74);
    result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPointInTouchHandlerRegion(
            test_point);
    EXPECT_FALSE(result_layer);
  
    // Hit checking for a point inside the touch event handler region should
    // return the root layer.
    test_point = gfx::Point(25, 25);
    result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPointInTouchHandlerRegion(
            test_point);
    ASSERT_TRUE(result_layer);
    EXPECT_EQ(456, result_layer->id());
  
    test_point = gfx::Point(34, 34);
    result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPointInTouchHandlerRegion(
            test_point);
    ASSERT_TRUE(result_layer);
    EXPECT_EQ(456, result_layer->id());
  }
  
  TEST_F(LayerTreeImplTest, HitCheckingTouchHandlerOverlappingRegions) {
    gfx::Transform identity_matrix;
    gfx::Point3F transform_origin;
  
    scoped_ptr<LayerImpl> root = LayerImpl::Create(host_impl().active_tree(), 1);
    SetLayerPropertiesForTesting(root.get(),
                                 identity_matrix,
                                 transform_origin,
                                 gfx::PointF(),
                                 gfx::Size(100, 100),
                                 true,
                                 false);
    {
      scoped_ptr<LayerImpl> touch_layer =
          LayerImpl::Create(host_impl().active_tree(), 123);
      // this layer is positioned, and hit testing should correctly know where the
      // layer is located.
      gfx::PointF position;
      gfx::Size bounds(50, 50);
      SetLayerPropertiesForTesting(touch_layer.get(),
                                   identity_matrix,
                                   transform_origin,
                                   position,
                                   bounds,
                                   true,
                                   false);
      touch_layer->SetDrawsContent(true);
      touch_layer->SetTouchEventHandlerRegion(gfx::Rect(0, 0, 50, 50));
      root->AddChild(touch_layer.Pass());
    }
  
    {
      scoped_ptr<LayerImpl> notouch_layer =
          LayerImpl::Create(host_impl().active_tree(), 1234);
      // this layer is positioned, and hit testing should correctly know where the
      // layer is located.
      gfx::PointF position(0, 25);
      gfx::Size bounds(50, 50);
      SetLayerPropertiesForTesting(notouch_layer.get(),
                                   identity_matrix,
                                   transform_origin,
                                   position,
                                   bounds,
                                   true,
                                   false);
      notouch_layer->SetDrawsContent(true);
      root->AddChild(notouch_layer.Pass());
    }
  
    host_impl().SetViewportSize(root->bounds());
    host_impl().active_tree()->SetRootLayer(root.Pass());
    host_impl().active_tree()->UpdateDrawProperties();
  
    // Sanity check the scenario we just created.
    ASSERT_EQ(1u, RenderSurfaceLayerList().size());
    ASSERT_EQ(2u, root_layer()->render_surface()->layer_list().size());
    ASSERT_EQ(123, root_layer()->render_surface()->layer_list().at(0)->id());
    ASSERT_EQ(1234, root_layer()->render_surface()->layer_list().at(1)->id());
  
    gfx::Point test_point(35, 35);
    LayerImpl* result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPointInTouchHandlerRegion(
            test_point);
  
    // We should have passed through the no-touch layer and found the layer
    // behind it.
    EXPECT_TRUE(result_layer);
  
    host_impl().active_tree()->LayerById(1234)->SetContentsOpaque(true);
    result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPointInTouchHandlerRegion(
            test_point);
  
    // Even with an opaque layer in the middle, we should still find the layer
    // with
    // the touch handler behind it (since we can't assume that opaque layers are
    // opaque to hit testing).
    EXPECT_TRUE(result_layer);
  
    test_point = gfx::Point(35, 15);
    result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPointInTouchHandlerRegion(
            test_point);
    ASSERT_TRUE(result_layer);
    EXPECT_EQ(123, result_layer->id());
  
    test_point = gfx::Point(35, 65);
    result_layer =
        host_impl().active_tree()->FindLayerThatIsHitByPointInTouchHandlerRegion(
            test_point);
    EXPECT_FALSE(result_layer);
  }
  
  TEST_F(LayerTreeImplTest, SelectionBoundsForSingleLayer) {
    int root_layer_id = 12345;
    scoped_ptr<LayerImpl> root =
        LayerImpl::Create(host_impl().active_tree(), root_layer_id);
  
    gfx::Transform identity_matrix;
    gfx::Point3F transform_origin;
    gfx::PointF position;
    gfx::Size bounds(100, 100);
    SetLayerPropertiesForTesting(root.get(),
                                 identity_matrix,
                                 transform_origin,
                                 position,
                                 bounds,
                                 true,
                                 false);
    root->SetDrawsContent(true);
  
    host_impl().SetViewportSize(root->bounds());
    host_impl().active_tree()->SetRootLayer(root.Pass());
    host_impl().active_tree()->UpdateDrawProperties();
  
    // Sanity check the scenario we just created.
    ASSERT_EQ(1u, RenderSurfaceLayerList().size());
    ASSERT_EQ(1u, root_layer()->render_surface()->layer_list().size());
  
    LayerSelectionBound left_input;
    left_input.type = SELECTION_BOUND_LEFT;
    left_input.layer_rect = gfx::RectF(10, 10, 5, 20);
    left_input.layer_id = root_layer_id;
  
    LayerSelectionBound right_input;
    right_input.type = SELECTION_BOUND_RIGHT;
    right_input.layer_rect = gfx::RectF(50, 10, 5, 20);
    right_input.layer_id = root_layer_id;
  
    ViewportSelectionBound left_output, right_output;
  
    // Empty input bounds should produce empty output bounds.
    host_impl().active_tree()->GetViewportSelection(&left_output, &right_output);
    EXPECT_EQ(ViewportSelectionBound(), left_output);
    EXPECT_EQ(ViewportSelectionBound(), right_output);
  
    // Selection bounds should produce distinct left and right bounds.
    host_impl().active_tree()->RegisterSelection(left_input, right_input);
    host_impl().active_tree()->GetViewportSelection(&left_output, &right_output);
    EXPECT_EQ(left_input.type, left_output.type);
    EXPECT_EQ(left_input.layer_rect, left_output.viewport_rect);
    EXPECT_TRUE(left_output.visible);
    EXPECT_EQ(right_input.type, right_output.type);
    EXPECT_EQ(right_input.layer_rect, right_output.viewport_rect);
    EXPECT_TRUE(right_output.visible);
  
    // Insertion bounds should produce identical left and right bounds.
    LayerSelectionBound insertion_input;
    insertion_input.type = SELECTION_BOUND_CENTER;
    insertion_input.layer_rect = gfx::RectF(10, 10, 5, 20);
    insertion_input.layer_id = root_layer_id;
    host_impl().active_tree()->RegisterSelection(insertion_input,
                                                 LayerSelectionBound());
    host_impl().active_tree()->GetViewportSelection(&left_output, &right_output);
    EXPECT_EQ(insertion_input.type, left_output.type);
    EXPECT_EQ(insertion_input.layer_rect, left_output.viewport_rect);
    EXPECT_TRUE(left_output.visible);
    EXPECT_EQ(left_output, right_output);
  }
  
  TEST_F(LayerTreeImplTest, SelectionBoundsForPartialOccludedLayers) {
    int root_layer_id = 12345;
    int clip_layer_id = 1234;
    int clipped_layer_id = 123;
    scoped_ptr<LayerImpl> root =
        LayerImpl::Create(host_impl().active_tree(), root_layer_id);
    root->SetDrawsContent(true);
  
    gfx::Transform identity_matrix;
    gfx::Point3F transform_origin;
    gfx::PointF position;
    gfx::Size bounds(100, 100);
    SetLayerPropertiesForTesting(root.get(),
                                 identity_matrix,
                                 transform_origin,
                                 position,
                                 bounds,
                                 true,
                                 false);
  
    gfx::Vector2dF clipping_offset(10, 10);
    {
      scoped_ptr<LayerImpl> clipping_layer =
          LayerImpl::Create(host_impl().active_tree(), clip_layer_id);
      // The clipping layer should occlude the right selection bound.
      gfx::PointF position = gfx::PointF() + clipping_offset;
      gfx::Size bounds(50, 50);
      SetLayerPropertiesForTesting(clipping_layer.get(),
                                   identity_matrix,
                                   transform_origin,
                                   position,
                                   bounds,
                                   true,
                                   false);
      clipping_layer->SetMasksToBounds(true);
  
      scoped_ptr<LayerImpl> clipped_layer =
          LayerImpl::Create(host_impl().active_tree(), clipped_layer_id);
      position = gfx::PointF();
      bounds = gfx::Size(100, 100);
      SetLayerPropertiesForTesting(clipped_layer.get(),
                                   identity_matrix,
                                   transform_origin,
                                   position,
                                   bounds,
                                   true,
                                   false);
      clipped_layer->SetDrawsContent(true);
      clipping_layer->AddChild(clipped_layer.Pass());
      root->AddChild(clipping_layer.Pass());
    }
  
    host_impl().SetViewportSize(root->bounds());
    host_impl().active_tree()->SetRootLayer(root.Pass());
    host_impl().active_tree()->UpdateDrawProperties();
  
    // Sanity check the scenario we just created.
    ASSERT_EQ(1u, RenderSurfaceLayerList().size());
  
    LayerSelectionBound left_input;
    left_input.type = SELECTION_BOUND_LEFT;
    left_input.layer_rect = gfx::RectF(25, 10, 5, 20);
    left_input.layer_id = clipped_layer_id;
  
    LayerSelectionBound right_input;
    right_input.type = SELECTION_BOUND_RIGHT;
    right_input.layer_rect = gfx::RectF(75, 10, 5, 20);
    right_input.layer_id = clipped_layer_id;
    host_impl().active_tree()->RegisterSelection(left_input, right_input);
  
    // The left bound should be occluded by the clip layer.
    ViewportSelectionBound left_output, right_output;
    host_impl().active_tree()->GetViewportSelection(&left_output, &right_output);
    EXPECT_EQ(left_input.type, left_output.type);
    gfx::RectF expected_left_output_rect = left_input.layer_rect;
    expected_left_output_rect.Offset(clipping_offset);
    EXPECT_EQ(expected_left_output_rect, left_output.viewport_rect);
    EXPECT_TRUE(left_output.visible);
    EXPECT_EQ(right_input.type, right_output.type);
    gfx::RectF expected_right_output_rect = right_input.layer_rect;
    expected_right_output_rect.Offset(clipping_offset);
    EXPECT_EQ(expected_right_output_rect, right_output.viewport_rect);
    EXPECT_FALSE(right_output.visible);
  
    // Handles outside the viewport bounds should be marked invisible.
    left_input.layer_rect = gfx::RectF(-25, 0, 5, 20);
    host_impl().active_tree()->RegisterSelection(left_input, right_input);
    host_impl().active_tree()->GetViewportSelection(&left_output, &right_output);
    EXPECT_FALSE(left_output.visible);
  
    left_input.layer_rect = gfx::RectF(0, -25, 5, 20);
    host_impl().active_tree()->RegisterSelection(left_input, right_input);
    host_impl().active_tree()->GetViewportSelection(&left_output, &right_output);
    EXPECT_FALSE(left_output.visible);
  
    // If the handle bottom is partially visible, the handle is marked visible.
    left_input.layer_rect = gfx::RectF(0, -20, 5, 21);
    host_impl().active_tree()->RegisterSelection(left_input, right_input);
    host_impl().active_tree()->GetViewportSelection(&left_output, &right_output);
    EXPECT_TRUE(left_output.visible);
  }
  
  TEST_F(LayerTreeImplTest, SelectionBoundsForScaledLayers) {
    int root_layer_id = 1;
    int sub_layer_id = 2;
    scoped_ptr<LayerImpl> root =
        LayerImpl::Create(host_impl().active_tree(), root_layer_id);
    root->SetDrawsContent(true);
  
    gfx::Transform identity_matrix;
    gfx::Point3F transform_origin;
    gfx::PointF position;
    gfx::Size bounds(100, 100);
    SetLayerPropertiesForTesting(root.get(),
                                 identity_matrix,
                                 transform_origin,
                                 position,
                                 bounds,
                                 true,
                                 false);
  
    gfx::Vector2dF sub_layer_offset(10, 0);
    {
      scoped_ptr<LayerImpl> sub_layer =
          LayerImpl::Create(host_impl().active_tree(), sub_layer_id);
      gfx::PointF position = gfx::PointF() + sub_layer_offset;
      gfx::Size bounds(50, 50);
      SetLayerPropertiesForTesting(sub_layer.get(),
                                   identity_matrix,
                                   transform_origin,
                                   position,
                                   bounds,
                                   true,
                                   false);
      sub_layer->SetDrawsContent(true);
      root->AddChild(sub_layer.Pass());
    }
  
    float device_scale_factor = 3.f;
    float page_scale_factor = 5.f;
    gfx::Size scaled_bounds_for_root = gfx::ToCeiledSize(
        gfx::ScaleSize(root->bounds(), device_scale_factor * page_scale_factor));
    host_impl().SetViewportSize(scaled_bounds_for_root);
  
    host_impl().SetDeviceScaleFactor(device_scale_factor);
    host_impl().active_tree()->SetPageScaleFactorAndLimits(
        page_scale_factor, page_scale_factor, page_scale_factor);
    host_impl().active_tree()->SetRootLayer(root.Pass());
    host_impl().active_tree()->SetViewportLayersFromIds(1, 1, Layer::INVALID_ID);
    host_impl().active_tree()->UpdateDrawProperties();
  
    // Sanity check the scenario we just created.
    ASSERT_EQ(1u, RenderSurfaceLayerList().size());
  
    LayerSelectionBound left_input;
    left_input.type = SELECTION_BOUND_LEFT;
    left_input.layer_rect = gfx::RectF(10, 10, 5, 20);
    left_input.layer_id = root_layer_id;
  
    LayerSelectionBound right_input;
    right_input.type = SELECTION_BOUND_RIGHT;
    right_input.layer_rect = gfx::RectF(0, 0, 5, 20);
    right_input.layer_id = sub_layer_id;
    host_impl().active_tree()->RegisterSelection(left_input, right_input);
  
    // The viewport bounds should be properly scaled by the page scale, but should
    // remain in DIP coordinates.
    ViewportSelectionBound left_output, right_output;
    host_impl().active_tree()->GetViewportSelection(&left_output, &right_output);
    EXPECT_EQ(left_input.type, left_output.type);
    gfx::RectF expected_left_output_rect = left_input.layer_rect;
    expected_left_output_rect.Scale(page_scale_factor);
    EXPECT_EQ(left_input.layer_rect, left_output.viewport_rect);
    EXPECT_TRUE(left_output.visible);
    EXPECT_EQ(right_input.type, right_output.type);
    gfx::RectF expected_right_output_rect = right_input.layer_rect;
    expected_right_output_rect.Offset(sub_layer_offset);
    expected_right_output_rect.Scale(page_scale_factor);
    EXPECT_EQ(expected_right_output_rect, right_output.viewport_rect);
    EXPECT_TRUE(right_output.visible);
  }
  
  TEST_F(LayerTreeImplTest, NumLayersTestOne) {
    EXPECT_EQ(0u, host_impl().active_tree()->NumLayers());
    scoped_ptr<LayerImpl> root = LayerImpl::Create(host_impl().active_tree(), 1);
    EXPECT_EQ(1u, host_impl().active_tree()->NumLayers());
  }
  
  TEST_F(LayerTreeImplTest, NumLayersSmallTree) {
    EXPECT_EQ(0u, host_impl().active_tree()->NumLayers());
    scoped_ptr<LayerImpl> root = LayerImpl::Create(host_impl().active_tree(), 1);
    root->AddChild(LayerImpl::Create(host_impl().active_tree(), 2));
    root->AddChild(LayerImpl::Create(host_impl().active_tree(), 3));
    root->child_at(1)->AddChild(LayerImpl::Create(host_impl().active_tree(), 4));
    EXPECT_EQ(4u, host_impl().active_tree()->NumLayers());
  }
  
  }  // namespace
  }  // namespace cc
  