Add VideoTrackSink interface to content/public

content/public/renderer/media_stream_video_sink.h

Index: content/public/renderer/media_stream_video_sink.h
diff --git a/content/public/renderer/media_stream_video_sink.h b/content/public/renderer/media_stream_video_sink.h
new file mode 100644
index 0000000000000000000000000000000000000000..a5b37da5c3fe9d2eacb419aa27f82fcfb4b2d8af
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+// 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_SINK_H_
+#define CONTENT_PUBLIC_RENDERER_MEDIA_STREAM_VIDEO_SINK_H_
+
+#include "base/compiler_specific.h"
+#include "base/memory/ref_counted.h"
+#include "content/common/content_export.h"
+#include "content/public/renderer/media_stream_sink.h"
+
+namespace media {
+class VideoFrame;
+}
+
+namespace blink {
+class WebMediaStreamTrack;
+}
+
+namespace content {
+
+// MediaStreamVideoSink is an interface used for receiving video frames from a
+// Video Stream Track or a Video Source.
+// http://dev.w3.org/2011/webrtc/editor/getusermedia.html
+// All methods calls will be done from the main render thread.
+class MediaStreamVideoSink : public MediaStreamSink {
+ public:
+  // An implementation of MediaStreamVideoSink should call AddToVideoTrack when
+  // it is ready to receive data from a video track. Before the implementation
+  // is destroyed, RemoveFromVideoTrack must be called.
+  // Calls to these methods must be done on the main render thread.
+  static void AddToVideoTrack(MediaStreamVideoSink* sink,
+                              const blink::WebMediaStreamTrack& track);
+  static void RemoveFromVideoTrack(MediaStreamVideoSink* sink,
+                                   const blink::WebMediaStreamTrack& track);
+
+  virtual void OnVideoFrame(const scoped_refptr<media::VideoFrame>& frame) = 0;
+
+ protected:
+  virtual ~MediaStreamVideoSink() {}
+};
+
+
+}  // namespace content
+
+#endif  // CONTENT_PUBLIC_RENDERER_MEDIA_STREAM_VIDEO_SINK_H_