Notify demux stream clients when a stream is disabled.

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 17f193f24acb06c420bd3f00f674da55778dd24f..c90de790abed2ab8c8e0119545b4e1979066bf49 100644
--- a/media/base/demuxer_stream.h
+++ b/media/base/demuxer_stream.h
@@ -102,9 +102,12 @@ class MEDIA_EXPORT DemuxerStream {
   // reading data from a key frame preceeding the |timestamp|.
   virtual void set_enabled(bool enabled, base::TimeDelta timestamp) = 0;
 
-  using StreamRestartedCB =
-      base::Callback<void(DemuxerStream*, base::TimeDelta)>;
-  virtual void SetStreamRestartedCB(const StreamRestartedCB& cb) = 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.