Generate and assign media track ids in demuxers.

media/filters/media_source_state.h

 // Copyright (c) 2016 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_FILTERS_MEDIA_SOURCE_STATE_H_
 #define MEDIA_FILTERS_MEDIA_SOURCE_STATE_H_
 
 #include <list>
 
 #include "base/bind.h"
@@ skipping 172 matching lines @@
 
   // Valid only while |parsing_media_segment_| is true. These flags enable
   // warning when at least one frame for each A/V track is not in a parsed media
   // segment.
   bool media_segment_contained_audio_frame_;
   bool media_segment_contained_video_frame_;
 
   // The object used to parse appended data.
   std::unique_ptr<StreamParser> stream_parser_;
 
-  std::unique_ptr<MediaTracks> media_tracks_;
-
   ChunkDemuxerStream* audio_;  // Not owned by |this|.
   ChunkDemuxerStream* video_;  // Not owned by |this|.
 
   typedef std::map<StreamParser::TrackId, ChunkDemuxerStream*> TextStreamMap;
   TextStreamMap text_stream_map_;  // |this| owns the map's stream pointers.
 
   std::unique_ptr<FrameProcessor> frame_processor_;
   scoped_refptr<MediaLog> media_log_;
   StreamParser::InitCB init_cb_;
 
@@ skipping 13 matching lines @@
   // TODO(wolenetz): Refactor this function while integrating April 29, 2014
   // changes to MSE spec. See http://crbug.com/371499.
   bool auto_update_timestamp_offset_;
 
   DISALLOW_COPY_AND_ASSIGN(MediaSourceState);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_FILTERS_MEDIA_SOURCE_STATE_H_