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..b79afa5a3f6050bb6f1a723c20cd425a39ef3d27 100644
--- a/content/browser/renderer_host/offscreen_canvas_compositor_frame_sink.h
+++ b/content/browser/renderer_host/offscreen_canvas_compositor_frame_sink.h
@@ -16,11 +16,13 @@ class OffscreenCanvasCompositorFrameSink
       public cc::SurfaceFactoryClient {
  public:
   OffscreenCanvasCompositorFrameSink(
+      uint32_t canvas_id,
       const cc::SurfaceId& surface_id,
       cc::mojom::MojoCompositorFrameSinkClientPtr client);
   ~OffscreenCanvasCompositorFrameSink() override;
 
-  static void Create(const cc::SurfaceId& surface_id,
+  static void Create(uint32_t canvas_id,
+                     const cc::SurfaceId& surface_id,
                      cc::mojom::MojoCompositorFrameSinkClientPtr client,
                      cc::mojom::MojoCompositorFrameSinkRequest request);
 
@@ -34,15 +36,22 @@ class OffscreenCanvasCompositorFrameSink
                        const gfx::Rect& damage_rect) override;
   void SetBeginFrameSource(cc::BeginFrameSource* begin_frame_source) override;
 
+  base::WeakPtr<OffscreenCanvasCompositorFrameSink> GetWeakPtr() {
+    return weak_factory_.GetWeakPtr();
+  }
+
  private:
   void DidReceiveCompositorFrameAck();
 
+  int canvas_id_;
   cc::SurfaceId surface_id_;
   std::unique_ptr<cc::SurfaceFactory> surface_factory_;
   cc::mojom::MojoCompositorFrameSinkClientPtr client_;
   int ack_pending_count_ = 0;
   cc::ReturnedResourceArray surface_returned_resources_;
 
+  base::WeakPtrFactory<OffscreenCanvasCompositorFrameSink> weak_factory_;
+
   DISALLOW_COPY_AND_ASSIGN(OffscreenCanvasCompositorFrameSink);
 };