Allow muting/unmuting audio through media track API

media/base/demuxer.h

 // Copyright (c) 2012 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 MEDIA_BASE_DEMUXER_H_
 #define MEDIA_BASE_DEMUXER_H_
 
 #include <stdint.h>
 
 #include <vector>
@@ skipping 49 matching lines @@
 class MEDIA_EXPORT Demuxer : public DemuxerStreamProvider {
  public:
   // A new potentially encrypted stream has been parsed.
   // First parameter - The type of initialization data.
   // Second parameter - The initialization data associated with the stream.
   typedef base::Callback<void(EmeInitDataType type,
                               const std::vector<uint8_t>& init_data)>
       EncryptedMediaInitDataCB;
 
   // Notifies demuxer clients that media track configuration has been updated
-  // (e.g. the inital stream metadata has been parsed successfully, or a new
+  // (e.g. the initial stream metadata has been parsed successfully, or a new
   // init segment has been parsed successfully in MSE case).
   typedef base::Callback<void(scoped_ptr<MediaTracks>)> MediaTracksUpdatedCB;
 
   Demuxer();
   ~Demuxer() override;
 
   // Returns the name of the demuxer for logging purpose.
   virtual std::string GetDisplayName() const = 0;
 
   // Completes initialization of the demuxer.
@@ skipping 46 matching lines @@
   virtual base::TimeDelta GetStartTime() const = 0;
 
   // Returns Time represented by presentation timestamp 0.
   // If the timstamps are not associated with a Time, then
   // a null Time is returned.
   virtual base::Time GetTimelineOffset() const = 0;
 
   // Returns the memory usage in bytes for the demuxer.
   virtual int64_t GetMemoryUsage() const = 0;
 
+  // Notifies the demuxer that track ids has been assigned to a media tracks.

[wolenetz, 2016/04/08 23:32:31]

nit: blink track ids, right?
nits: Also, s/has/have/ and s/a media tracks/|tracks|/.

[servolk, 2016/04/08 23:47:20]

Done.

+  virtual void OnTrackIdsAssigned(const MediaTracks& tracks,
+                                  const std::vector<unsigned>& track_ids) = 0;

[wolenetz, 2016/04/08 23:32:31]

Comment is needed to describe that |tracks|.tracks() size must be the same as
|track_ids|, and that their sequences match, such that the association of each
track id to a MediaTrack is well-defined here.

[servolk, 2016/04/08 23:47:20]

Done.

+
+  // Finds a DemuxerStream corresponding to the given blink |track_id|. Note
+  // that the input track id is blink track id and not bytestream track id.
+  virtual const DemuxerStream* GetDemuxerStreamByTrackId(
+      unsigned track_id) const = 0;
+
  private:
   DISALLOW_COPY_AND_ASSIGN(Demuxer);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_BASE_DEMUXER_H_