cc: Introduce BeginFrame sequence numbers and acknowledgements.

cc/surfaces/compositor_frame_sink_support.h

 // Copyright 2016 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_SURFACES_COMPOSITOR_FRAME_SINK_SUPPORT_H_
 #define CC_SURFACES_COMPOSITOR_FRAME_SINK_SUPPORT_H_
 
 #include "base/compiler_specific.h"
 #include "base/memory/weak_ptr.h"
 #include "cc/output/compositor_frame.h"
@@ skipping 21 matching lines @@
                              std::unique_ptr<Display> display);
 
   ~CompositorFrameSinkSupport() override;
 
   const FrameSinkId& frame_sink_id() const { return frame_sink_id_; }
 
   void EvictFrame();
   void SetNeedsBeginFrame(bool needs_begin_frame);
   void SubmitCompositorFrame(const LocalFrameId& local_frame_id,
                              CompositorFrame frame);
+  void BeginFrameDidNotDraw(const BeginFrameAck& ack);
   void AddChildFrameSink(const FrameSinkId& child_frame_sink_id);
   void RemoveChildFrameSink(const FrameSinkId& child_frame_sink_id);
 
  private:
   void DidReceiveCompositorFrameAck();
 
   // DisplayClient implementation.
   void DisplayOutputSurfaceLost() override;
   void DisplayWillDrawAndSwap(bool will_draw_and_swap,
                               const RenderPassList& render_passes) override;
@@ skipping 43 matching lines @@
   bool added_frame_observer_ = false;
 
   base::WeakPtrFactory<CompositorFrameSinkSupport> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(CompositorFrameSinkSupport);
 };
 
 }  // namespace cc
 
 #endif  // CC_SURFACES_COMPOSITOR_FRAME_SINK_SUPPORT_H_