WIP: Surface Synchronization System

services/ui/public/cpp/window_compositor_frame_sink.h

Index: services/ui/public/cpp/window_compositor_frame_sink.h
diff --git a/services/ui/public/cpp/window_compositor_frame_sink.h b/services/ui/public/cpp/window_compositor_frame_sink.h
index 17d5988d99d7ce650ac7d9eab2b03719563d1fa3..796f4255a979d3d4eb590f9df888e368926edae2 100644
--- a/services/ui/public/cpp/window_compositor_frame_sink.h
+++ b/services/ui/public/cpp/window_compositor_frame_sink.h
@@ -33,6 +33,10 @@ class WindowCompositorFrameSink
 
   ~WindowCompositorFrameSink() override;
 
+  base::WeakPtr<WindowCompositorFrameSink> GetWeakPtr();
+
+  void SetLocalFrameId(const cc::LocalFrameId& local_frame_id);
+
   // cc::CompositorFrameSink implementation.
   bool BindToClient(cc::CompositorFrameSinkClient* client) override;
   void DetachFromClient() override;
@@ -66,6 +70,9 @@ class WindowCompositorFrameSink
       client_binding_;
   std::unique_ptr<base::ThreadChecker> thread_checker_;
   const cc::FrameSinkId frame_sink_id_;
+  base::Optional<cc::CompositorFrame> pending_compositor_frame_;
+
+  base::WeakPtrFactory<WindowCompositorFrameSink> factory_;
 
   DISALLOW_COPY_AND_ASSIGN(WindowCompositorFrameSink);
 };