Cast: deliver video frames on the IO thread

content/renderer/media/media_stream_video_track.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_RENDERER_MEDIA_MEDIA_STREAM_VIDEO_TRACK_H_
 #define CONTENT_RENDERER_MEDIA_MEDIA_STREAM_VIDEO_TRACK_H_
 
 #include <vector>
 
 #include "base/compiler_specific.h"
@@ skipping 30 matching lines @@
       const blink::WebMediaStreamTrack& track);
 
   // Constructor for local video tracks.
    MediaStreamVideoTrack(
        MediaStreamVideoSource* source,
        const blink::WebMediaConstraints& constraints,
        const MediaStreamVideoSource::ConstraintsCallback& callback,
        bool enabled);
   virtual ~MediaStreamVideoTrack();
 
-  // Add |sink| to receive state changes and video frames on the main render
-  // thread.
-  virtual void AddSink(MediaStreamVideoSink* sink);
-  virtual void RemoveSink(MediaStreamVideoSink* sink);
-
   // Add |sink| to receive state changes on the main render thread and video
   // frames in the |callback| method on the IO-thread.
-  virtual void AddSink(MediaStreamSink* sink,
+  virtual void AddSink(MediaStreamVideoSink* sink,
                        const VideoCaptureDeliverFrameCB& callback);
-  virtual void RemoveSink(MediaStreamSink* sink);
+  virtual void RemoveSink(MediaStreamVideoSink* sink);
 
   virtual void SetEnabled(bool enabled) OVERRIDE;
   virtual void Stop() OVERRIDE;
 
   void OnReadyStateChanged(blink::WebMediaStreamSource::ReadyState state);
 
   const blink::WebMediaConstraints& constraints() const {
     return constraints_;
   }
 
@@ skipping 13 matching lines @@
   // by the blink::WebMediaStreamSource and is guaranteed to outlive the
   // track.
   MediaStreamVideoSource* source_;
 
   DISALLOW_COPY_AND_ASSIGN(MediaStreamVideoTrack);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_MEDIA_MEDIA_STREAM_VIDEO_TRACK_H_