Convert offscreen canvas to use FrameSinkManagerHost.

content/browser/renderer_host/offscreen_canvas_surface_impl.h

Index: content/browser/renderer_host/offscreen_canvas_surface_impl.h
diff --git a/content/browser/renderer_host/offscreen_canvas_surface_impl.h b/content/browser/renderer_host/offscreen_canvas_surface_impl.h
index ab3bcb2785b1c71e83cc277e5214197895660ac9..3f76a2b41cf6632702c485fce1fb11a6984505bf 100644
--- a/content/browser/renderer_host/offscreen_canvas_surface_impl.h
+++ b/content/browser/renderer_host/offscreen_canvas_surface_impl.h
@@ -7,12 +7,13 @@
 
 #include "cc/ipc/frame_sink_manager.mojom.h"
 #include "cc/surfaces/surface_id.h"
-#include "mojo/public/cpp/bindings/interface_request.h"
 #include "mojo/public/cpp/bindings/strong_binding.h"
 #include "third_party/WebKit/public/platform/modules/offscreencanvas/offscreen_canvas_surface.mojom.h"
 
 namespace content {
 
+// The browser owned object for an offscreen canvas connection. Holds
+// connections to both the renderer and frame sink manager.
 class CONTENT_EXPORT OffscreenCanvasSurfaceImpl
     : public blink::mojom::OffscreenCanvasSurface {
  public:
@@ -26,6 +27,14 @@ class CONTENT_EXPORT OffscreenCanvasSurfaceImpl
                      cc::mojom::FrameSinkManagerClientPtr client,
                      blink::mojom::OffscreenCanvasSurfaceRequest request);
 
+  // Creates a MojoCompositorFrameSink connection to FrameSinkManager for an
+  // offscreen canvas client. The corresponding private interface will be owned
+  // here to control CompositorFrameSink lifetime. This should only ever be
+  // called once.
+  void CreateCompositorFrameSink(
+      cc::mojom::MojoCompositorFrameSinkClientPtr client,
+      cc::mojom::MojoCompositorFrameSinkRequest request);
+
   void OnSurfaceCreated(const cc::SurfaceInfo& surface_info);
 
   // blink::mojom::OffscreenCanvasSurface implementation.
@@ -47,11 +56,18 @@ class CONTENT_EXPORT OffscreenCanvasSurfaceImpl
   cc::mojom::FrameSinkManagerClientPtr client_;
   mojo::StrongBindingPtr<blink::mojom::OffscreenCanvasSurface> binding_;
 
+  // Private connection for the CompositorFrameSink. The CompositorFrameSink
+  // will not be destroyed until both private and offscreen canvas client
+  // connections are closed.
+  cc::mojom::MojoCompositorFrameSinkPrivatePtr compositor_frame_sink_private_;
+
   // Surface-related state
   const cc::FrameSinkId frame_sink_id_;
   cc::LocalSurfaceId current_local_surface_id_;
   const cc::FrameSinkId parent_frame_sink_id_;
 
+  bool has_created_compositor_frame_sink_ = false;
+
   DISALLOW_COPY_AND_ASSIGN(OffscreenCanvasSurfaceImpl);
 };