text: // Copyright 2011 The Chromium Authors. All rights reserved.
  // Use of this source code is governed by a BSD-style license that can be
  // found in the LICENSE file.
  
  #ifndef CC_TREES_PROXY_H_
  #define CC_TREES_PROXY_H_
  
  #include <memory>
  #include <string>
  
  #include "base/memory/ref_counted.h"
  #include "base/threading/platform_thread.h"
  #include "base/time/time.h"
  #include "base/values.h"
  #include "cc/cc_export.h"
  #include "cc/input/browser_controls_state.h"
  #include "cc/trees/paint_holding_commit_trigger.h"
  #include "cc/trees/task_runner_provider.h"
  #include "components/viz/common/frame_sinks/begin_frame_source.h"
  #include "services/metrics/public/cpp/ukm_source_id.h"
  #include "url/gurl.h"
  
  namespace gfx {
  class Rect;
  }
  
  namespace cc {
  class LayerTreeFrameSink;
  class LayerTreeMutator;
  class PaintWorkletLayerPainter;
  class RenderFrameMetadataObserver;
  
  // Abstract interface responsible for proxying commands from the main-thread
  // side of the compositor over to the compositor implementation.
  class CC_EXPORT Proxy {
   public:
    virtual ~Proxy() {}
  
    virtual bool IsStarted() const = 0;
  
    virtual void SetLayerTreeFrameSink(
        LayerTreeFrameSink* layer_tree_frame_sink) = 0;
    virtual void ReleaseLayerTreeFrameSink() = 0;
  
    virtual void SetVisible(bool visible) = 0;
  
    virtual void SetNeedsAnimate() = 0;
    virtual void SetNeedsUpdateLayers() = 0;
    virtual void SetNeedsCommit() = 0;
    virtual void SetNeedsRedraw(const gfx::Rect& damage_rect) = 0;
    virtual void SetNextCommitWaitsForActivation() = 0;
  
    // Returns true if an animate or commit has been requested, and hasn't
    // completed yet.
    virtual bool RequestedAnimatePending() = 0;
  
    // Defers LayerTreeHost::BeginMainFrameUpdate and commits until it is
    // reset. It is only supported when using a scheduler.
    virtual void SetDeferMainFrameUpdate(bool defer_main_frame_update) = 0;
  
    // Defers commits until at most the given |timeout| period has passed,
    // but continues to update the document lifecycle in
    // LayerTreeHost::BeginMainFrameUpdate. If multiple calls are made when
    // deferal is active the first |timeout| continues to apply.
    virtual void StartDeferringCommits(base::TimeDelta timeout) = 0;
  
    // Immediately stop deferring commits.
    virtual void StopDeferringCommits(PaintHoldingCommitTrigger) = 0;
  
    virtual bool CommitRequested() const = 0;
  
    // Must be called before using the proxy.
    virtual void Start() = 0;
    // Must be called before deleting the proxy.
    virtual void Stop() = 0;
  
    virtual void SetMutator(std::unique_ptr<LayerTreeMutator> mutator) = 0;
  
    virtual void SetPaintWorkletLayerPainter(
        std::unique_ptr<PaintWorkletLayerPainter> painter) = 0;
  
    virtual void UpdateBrowserControlsState(BrowserControlsState constraints,
                                            BrowserControlsState current,
                                            bool animate) = 0;
  
    virtual void RequestBeginMainFrameNotExpected(bool new_state) = 0;
  
    // Testing hooks
    virtual bool MainFrameWillHappenForTesting() = 0;
  
    virtual void SetSourceURL(ukm::SourceId source_id, const GURL& url) = 0;
  
    virtual void SetUkmSmoothnessDestination(
        base::WritableSharedMemoryMapping ukm_smoothness_data) = 0;
  
    virtual void ClearHistory() = 0;
  
    virtual void SetRenderFrameObserver(
        std::unique_ptr<RenderFrameMetadataObserver> observer) = 0;
  
    virtual void SetEnableFrameRateThrottling(
        bool enable_frame_rate_throttling) = 0;
  };
  
  }  // namespace cc
  
  #endif  // CC_TREES_PROXY_H_
  