Refactor MediaResource to be multi-stream capable

media/base/demuxer_stream.h

Index: media/base/demuxer_stream.h
diff --git a/media/base/demuxer_stream.h b/media/base/demuxer_stream.h
index 82d5d048318fad1994c5b8fd445fad527f39e93c..366d26e0ea660944b0d84ad219ab2063f5b52508 100644
--- a/media/base/demuxer_stream.h
+++ b/media/base/demuxer_stream.h
@@ -104,13 +104,6 @@ class MEDIA_EXPORT DemuxerStream {
   // reading data from a key frame preceeding the |timestamp|.
   virtual void set_enabled(bool enabled, base::TimeDelta timestamp) = 0;
 
-  // The StreamStatusChangeCB allows DemuxerStream clients to receive
-  // notifications about the stream being disabled or enabled.
-  // The first parameter indicates whether the stream is enabled or disabled.
-  // The second parameter is the playback position when the change occured.
-  using StreamStatusChangeCB = base::Callback<void(bool, base::TimeDelta)>;
-  virtual void SetStreamStatusChangeCB(const StreamStatusChangeCB& cb) = 0;
-
  protected:
   // Only allow concrete implementations to get deleted.
   virtual ~DemuxerStream();