OutputSurfaceMojo should bind its SurfacePtr on the impl thread

mojo/cc/output_surface_mojo.h

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef MOJO_CC_OUTPUT_SURFACE_MOJO_H_
 #define MOJO_CC_OUTPUT_SURFACE_MOJO_H_
 
 #include "cc/output/output_surface.h"
 #include "cc/surfaces/surface_id.h"
 #include "cc/surfaces/surface_id_allocator.h"
@@ skipping 13 matching lines @@
   OutputSurfaceMojo(OutputSurfaceMojoClient* client,
                     const scoped_refptr<cc::ContextProvider>& context_provider,
                     SurfacePtr surface,
                     uint32_t id_namespace);
 
   // SurfaceClient implementation.
   virtual void ReturnResources(Array<ReturnedResourcePtr> resources) OVERRIDE;
 
   // cc::OutputSurface implementation.
   virtual void SwapBuffers(cc::CompositorFrame* frame) OVERRIDE;
+  virtual bool BindToClient(cc::OutputSurfaceClient* client) OVERRIDE;
 
  protected:
   virtual ~OutputSurfaceMojo();
 
  private:
   OutputSurfaceMojoClient* output_surface_mojo_client_;
   SurfacePtr surface_;
   cc::SurfaceIdAllocator id_allocator_;
   cc::SurfaceId surface_id_;
   gfx::Size surface_size_;
 
   DISALLOW_COPY_AND_ASSIGN(OutputSurfaceMojo);
 };
 }
 
 #endif  // MOJO_CC_OUTPUT_SURFACE_MOJO_H_