MediaVideoStreamTrack should store weak reference to the media source.

content/renderer/media/media_stream_video_track.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_RENDERER_MEDIA_MEDIA_STREAM_VIDEO_TRACK_H_
 #define CONTENT_RENDERER_MEDIA_MEDIA_STREAM_VIDEO_TRACK_H_
 
 #include <vector>
 
 #include "base/compiler_specific.h"
@@ skipping 68 matching lines @@
 
   std::vector<MediaStreamVideoSink*> sinks_;
 
   // |FrameDeliverer| is an internal helper object used for delivering video
   // frames on the IO-thread using callbacks to all registered tracks.
   class FrameDeliverer;
   const scoped_refptr<FrameDeliverer> frame_deliverer_;
 
   const blink::WebMediaConstraints constraints_;
 
-  // Weak ref to the source this tracks is connected to.  |source_| is owned
-  // by the blink::WebMediaStreamSource and is guaranteed to outlive the
-  // track.
-  MediaStreamVideoSource* source_;
+  // Weak ref to the source this tracks is connected to.
+  base::WeakPtr<MediaStreamVideoSource> source_;
 
   // This is used for tracking if all connected video sinks are secure.
   SecureDisplayLinkTracker<MediaStreamVideoSink> secure_tracker_;
 
   DISALLOW_COPY_AND_ASSIGN(MediaStreamVideoTrack);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_MEDIA_MEDIA_STREAM_VIDEO_TRACK_H_