Implements MediaStreamVideoSource.

content/renderer/media/media_stream_video_source.h

Index: content/renderer/media/media_stream_video_source.h
===================================================================
--- content/renderer/media/media_stream_video_source.h	(revision 244998)
+++ content/renderer/media/media_stream_video_source.h	(working copy)
@@ -19,6 +19,8 @@
 
 namespace content {
 
+class MediaStreamDependencyFactory;
+
 // MediaStreamVideoSource is an interface used for sending video frames to a
 // MediaStreamVideoTrack.
 // http://dev.w3.org/2011/webrtc/editor/getusermedia.html
@@ -26,23 +28,51 @@
 class CONTENT_EXPORT MediaStreamVideoSource
     : public MediaStreamSourceExtraData {
  public:
+  explicit MediaStreamVideoSource(
+      MediaStreamDependencyFactory* factory);
+
   // Puts |track| in the registered tracks list. Will later
   // deliver frames to it according to |constraints|.
-  void AddTrack(const blink::WebMediaStreamTrack& track,
-                const blink::WebMediaConstraints& constraints);
+  virtual void AddTrack(const blink::WebMediaStreamTrack& track,
+                        const blink::WebMediaConstraints& constraints);
 
   // Removes |track| from the registered tracks list, i.e. will stop delivering
   // frame to |track|.
-  void RemoveTrack(const blink::WebMediaStreamTrack& track);
+  virtual void RemoveTrack(const blink::WebMediaStreamTrack& track);
 
+  // TODO(ronghuawu): Remove webrtc::VideoSourceInterface from the public
+  // interface of this class.
+  webrtc::VideoSourceInterface* GetAdapter() {
+    return adapter_;
+  }
+
  protected:
+  // Sets an external adapter. Must be called before Init, which creates a
+  // default adapter if the adapter is not set already.
+  void SetAdapter(webrtc::VideoSourceInterface* adapter) {
+    DCHECK(!adapter_);
+    adapter_ = adapter;
+  }
+
+  // Called by the derived class before any other methods except SetAdapter.
+  void Init();
+
   // Sets ready state and notifies the ready state to all registered tracks.
   virtual void SetReadyState(blink::WebMediaStreamSource::ReadyState state);
 
   // Delivers |frame| to registered tracks according to their constraints.
+  // Note: current implementation assumes |frame| be contiguous layout of image
+  // planes and I420.
   virtual void DeliverVideoFrame(const scoped_refptr<media::VideoFrame>& frame);
 
   virtual ~MediaStreamVideoSource();
+
+ private:
+  MediaStreamDependencyFactory* factory_;
+  scoped_refptr<webrtc::VideoSourceInterface> adapter_;
+  int width_;
+  int height_;
+  base::TimeDelta first_frame_timestamp_;
 };
 
 }  // namespace content