Create manager to track OffscreenCanvasSurfaceImpl instances

content/browser/renderer_host/offscreen_canvas_compositor_frame_sink.h

Index: content/browser/renderer_host/offscreen_canvas_compositor_frame_sink.h
diff --git a/content/browser/renderer_host/offscreen_canvas_compositor_frame_sink.h b/content/browser/renderer_host/offscreen_canvas_compositor_frame_sink.h
index 0d838ed11ee7831824cd70a4c261ecee3962336f..6563fceb8347745a3c62fceb7c2dc76e9f9c855c 100644
--- a/content/browser/renderer_host/offscreen_canvas_compositor_frame_sink.h
+++ b/content/browser/renderer_host/offscreen_canvas_compositor_frame_sink.h
@@ -11,7 +11,7 @@
 
 namespace content {
 
-class OffscreenCanvasCompositorFrameSink
+class CONTENT_EXPORT OffscreenCanvasCompositorFrameSink
     : public cc::mojom::MojoCompositorFrameSink,
       public cc::SurfaceFactoryClient {
  public:
@@ -34,6 +34,10 @@ class OffscreenCanvasCompositorFrameSink
                        const gfx::Rect& damage_rect) override;
   void SetBeginFrameSource(cc::BeginFrameSource* begin_frame_source) override;
 
+  const cc::FrameSinkId& frame_sink_id() const {

[Fady Samuel, 2016/11/15 19:27:52]

Is exposing this necessary?

[xlai (Olivia), 2016/11/15 20:07:47]

It's not necessary after *Manager and *CompositorFrameSink are made
dis-associated in later patches. Removing it now.

+    return surface_id_.frame_sink_id();
+  }
+
  private:
   void DidReceiveCompositorFrameAck();