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..a2e6c55ec7da1bbf771dd36c8475c5175674bd2a 100644
--- a/media/base/demuxer_stream.h
+++ b/media/base/demuxer_stream.h
@@ -102,9 +102,14 @@ 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 is the DemuxerStream whose status has changed.
+  // The second parameter indicates whether the stream is enabled or disabled.
+  // The third parameter is the playback position when the change occured.
+  using StreamStatusChangeCB =

[alokp, 2016/08/04 19:02:36]

nit: is it necessary for the callback to specify the DemuxerStream? Can't the
client bind the demuxer-stream locally when constructing the callback?

[servolk, 2016/08/04 20:31:47]

Done.

+      base::Callback<void(DemuxerStream*, bool, base::TimeDelta)>;
+  virtual void SetStreamStatusChangeCB(const StreamStatusChangeCB& cb) = 0;
 
  protected:
   // Only allow concrete implementations to get deleted.