Add VideoTrackSink interface to content/public

content/public/renderer/media_stream_video_sink.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_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 CONTENT_EXPORT MediaStreamVideoSink : public MediaStreamSink {

[jam, 2013/12/03 00:48:20]

nit: export not needed

[perkj_chrome, 2013/12/03 16:14:17]

Done.

+ public:
+  virtual void OnVideoFrame(const scoped_refptr<media::VideoFrame>& frame) = 0;
+
+ protected:
+  virtual ~MediaStreamVideoSink() {}
+};
+
+// 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.
+CONTENT_EXPORT void AddToVideoTrack(MediaStreamVideoSink* sink,
+                                    const blink::WebMediaStreamTrack& track);
+CONTENT_EXPORT void RemoveFromVideoTrack(

[jam, 2013/12/03 00:48:20]

please move these two methods to be inside MediaStreamVideoSink, as we try to
avoid static methods in the content namespace.

i.e.

class MediaStreamVideoSink : public MedaiStreamSink {
 public:
  static Add(...);
  static Remove(...);

  virtual void OnVideoFrame(...);

[perkj_chrome, 2013/12/03 16:14:17]

Done.

+    MediaStreamVideoSink* sink,
+    const blink::WebMediaStreamTrack& track);
+
+}  // namespace content
+
+#endif  // CONTENT_PUBLIC_RENDERER_MEDIA_STREAM_VIDEO_SINK_H_