MediaVideoStreamTrack should store weak reference to the media source.

content/renderer/media/media_stream_video_source.h

 // Copyright 2014 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_SOURCE_H_
 #define CONTENT_RENDERER_MEDIA_MEDIA_STREAM_VIDEO_SOURCE_H_
 
 #include <string>
 #include <vector>
 
@@ skipping 80 matching lines @@
   virtual void RequestRefreshFrame() {}
 
   // Notify underlying source if the capturing link is secure.
   virtual void SetCapturingLinkSecured(bool is_secure) {}
 
   // Returns the task runner where video frames will be delivered on.
   base::SingleThreadTaskRunner* io_task_runner() const;
 
   const media::VideoCaptureFormat* GetCurrentFormat() const;
 
+  base::WeakPtr<MediaStreamVideoSource> GetWeakPtr() {
+    return weak_factory_.GetWeakPtr();
+  }
+
  protected:
   void DoStopSource() override;
 
   // Sets ready state and notifies the ready state to all registered tracks.
   virtual void SetReadyState(blink::WebMediaStreamSource::ReadyState state);
 
   // Sets muted state and notifies it to all registered tracks.
   virtual void SetMutedState(bool state);
 
   // An implementation must fetch the formats that can currently be used by
@@ skipping 87 matching lines @@
 
   // NOTE: Weak pointers must be invalidated before all other member variables.
   base::WeakPtrFactory<MediaStreamVideoSource> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(MediaStreamVideoSource);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_MEDIA_MEDIA_STREAM_VIDEO_SOURCE_H_