Move passing of WebRTC rendering frames from main thread to compositor thread

content/public/renderer/media_stream_video_renderer.h

 // Copyright 2013 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 CONTENT_PUBLIC_RENDERER_MEDIA_STREAM_VIDEO_RENDERER_H_
 #define CONTENT_PUBLIC_RENDERER_MEDIA_STREAM_VIDEO_RENDERER_H_
 
 #include "base/callback.h"
 #include "base/memory/ref_counted.h"
 
 namespace media {
 class VideoFrame;
 }
 
 namespace content {
 
 // Interface returned by MediaStreamRendererFactory that provides controls for
 // the flow of video frame callbacks being made.
 // TODO(wjia): remove ref count.
 class MediaStreamVideoRenderer
     : public base::RefCountedThreadSafe<MediaStreamVideoRenderer> {
  public:
-  typedef base::Callback<void(const scoped_refptr<media::VideoFrame>&)>
-      RepaintCB;
+  typedef base::Callback<void(scoped_refptr<media::VideoFrame>)> RepaintCB;
 
   // Start to provide video frames to the caller.
   virtual void Start() = 0;
 
   // Stop to provide video frames to the caller.
   virtual void Stop() = 0;
 
   // Resume to provide video frames to the caller after being paused.
   virtual void Resume() = 0;
 
   // Put the provider in pause state and the caller will not receive video
   // frames, but the provider might still generate video frames which are
   // thrown away.
   virtual void Pause() = 0;
 
  protected:
   friend class base::RefCountedThreadSafe<MediaStreamVideoRenderer>;
 
   virtual ~MediaStreamVideoRenderer() {}
 
 };
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_RENDERER_MEDIA_STREAM_VIDEO_RENDERER_H_