Mus+Ash: Unified BeginFrame Skeleton

ui/aura/mus/window_compositor_frame_sink.h

Index: ui/aura/mus/window_compositor_frame_sink.h
diff --git a/ui/aura/mus/window_compositor_frame_sink.h b/ui/aura/mus/window_compositor_frame_sink.h
index b63fab0175894c9b038f5da2109d8ce687a6a48b..84db67e04438ebce36b5838b8f3a651b3ba6be9a 100644
--- a/ui/aura/mus/window_compositor_frame_sink.h
+++ b/ui/aura/mus/window_compositor_frame_sink.h
@@ -22,7 +22,8 @@ class WindowCompositorFrameSinkBinding;
 
 class WindowCompositorFrameSink
     : public cc::CompositorFrameSink,
-      public cc::mojom::MojoCompositorFrameSinkClient {
+      public cc::mojom::MojoCompositorFrameSinkClient,
+      public cc::ExternalBeginFrameSourceClient {
  public:
   // static
   static std::unique_ptr<WindowCompositorFrameSink> Create(
@@ -48,9 +49,13 @@ class WindowCompositorFrameSink
 
   // cc::mojom::MojoCompositorFrameSinkClient implementation:
   void DidReceiveCompositorFrameAck() override;
+  void OnBeginFrame(const cc::BeginFrameArgs& begin_frame_args) override;
   void ReclaimResources(const cc::ReturnedResourceArray& resources) override;
 
-  std::unique_ptr<cc::BeginFrameSource> begin_frame_source_;
+  // cc::ExternalBeginFrameSourceClient implementation.
+  void OnNeedsBeginFrames(bool needs_begin_frames) override;
+
+  std::unique_ptr<cc::ExternalBeginFrameSource> begin_frame_source_;
   mojo::InterfacePtrInfo<cc::mojom::MojoCompositorFrameSink>
       compositor_frame_sink_info_;
   mojo::InterfaceRequest<cc::mojom::MojoCompositorFrameSinkClient>