Add VideoTrackSink interface to content/public

content/public/renderer/media/video_track_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_VIDEO_TRACK_SINK_H_
+#define CONTENT_PUBLIC_RENDERER_MEDIA_VIDEO_TRACK_SINK_H_
+
+#include "base/compiler_specific.h"
+#include "base/memory/ref_counted.h"
+#include "content/common/content_export.h"
+#include "content/public/renderer/media/media_track_sink.h"
+
+namespace media {
+class VideoFrame;
+}
+
+namespace blink {
+class WebMediaStreamSource;
+class WebMediaStreamTrack;
+}
+
+namespace content {
+
+class CONTENT_EXPORT VideoTrackSink : public MediaTrackSink {
+ public:
+  virtual void OnVideoFrame(const scoped_refptr<media::VideoFrame>& frame) = 0;
+
+ protected:
+  virtual ~VideoTrackSink() {}
+
+  // An implementation should call Register when it is ready to receive
+  // data from a track. Before the implementation is destroyed, Unregister must
+  // be called.
+  void Register(const blink::WebMediaStreamTrack& track);

[no longer working on chromium, 2013/11/25 13:55:07]

Can AddSink, RemoveSink better names than Register and UnRegister ?

[Jói, 2013/11/25 14:06:55]

Registration and unregistration should be on the VideoTrack object itself.

VideoTrack could have a FromBlinkTrack static method, then instead of calling
this->Register(blink_track) on itself, a sink would call
FromBlinkTrack(blink_track)->Register(this);

[Alpha Left Google, 2013/11/26 04:59:32]

I'm not sure this is possible unless VideoTrack is also in
content/public/renderer. It looks like VideoTrack is the implementation of a
video track which shouldn't be exposed to content/public. I think these can just
be some static methods like this:

namespace content {

class VideoTrackSink : public MediaTrackSink {
 public:
  virtual void OnVideoFrame(...) = 0;
};

// static
void AddSinkToVideoTrack(VideoTrackSink*, const blink::WebMediaStreamTrack&
track);
void RemoveSinkFromVideoTrack(const blink::WebMediaStreamTrack& track);

} // namespace content

[perkj_chrome, 2013/11/26 09:16:38]

Done.

[perkj_chrome, 2013/11/26 09:16:38]

Joi? I use static functions at the moment. It seems like the static methods must
belong to the class.

[Jói, 2013/11/26 10:18:15]

Yeah, makes sense to have static functions on VideoTrackSink to
register/unregister given a WebMediaStreamTrack.

+  void UnRegister(const blink::WebMediaStreamTrack& track);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_PUBLIC_RENDERER_MEDIA_VIDEO_TRACK_SINK_H_