Support multiple media tracks in MSE / ChunkDemuxer

media/filters/chunk_demuxer.h

Index: media/filters/chunk_demuxer.h
diff --git a/media/filters/chunk_demuxer.h b/media/filters/chunk_demuxer.h
index 3d0409e90f74051a1852a25ca07df48d404f7dd4..f8a438213c33ae4bd11082edb6da4eeef0dddfe1 100644
--- a/media/filters/chunk_demuxer.h
+++ b/media/filters/chunk_demuxer.h
@@ -217,8 +217,9 @@ class MEDIA_EXPORT ChunkDemuxer : public Demuxer {
   // kNotSupported is returned if |type| is not a supported format.
   // kReachedIdLimit is returned if the demuxer cannot handle another ID right
   //    now.
-  Status AddId(const std::string& id, const std::string& type,
-               std::vector<std::string>& codecs);
+  Status AddId(const std::string& id,
+               const std::string& type,
+               const std::string& codecs);
 
   // Notifies a caller via |tracks_updated_cb| that the set of media tracks
   // for a given |id| has changed.
@@ -408,8 +409,8 @@ class MEDIA_EXPORT ChunkDemuxer : public Demuxer {
   // http://crbug.com/308226
   PipelineStatusCB seek_cb_;
 
-  std::unique_ptr<ChunkDemuxerStream> audio_;
-  std::unique_ptr<ChunkDemuxerStream> video_;
+  std::vector<std::unique_ptr<ChunkDemuxerStream>> audio_streams_;
+  std::vector<std::unique_ptr<ChunkDemuxerStream>> video_streams_;
 
   // Counter to ensure that we do not transition too early to INITIALIZED.
   // Incremented in AddId(), decremented in OnSourceInitDone().
@@ -430,12 +431,6 @@ class MEDIA_EXPORT ChunkDemuxer : public Demuxer {
   typedef std::map<std::string, MediaSourceState*> MediaSourceStateMap;
   MediaSourceStateMap source_state_map_;
 
-  // Used to ensure that (1) config data matches the type and codec provided in
-  // AddId(), (2) only 1 audio and 1 video sources are added, and (3) ids may be
-  // removed with RemoveID() but can not be re-added (yet).
-  std::string source_id_audio_;
-  std::string source_id_video_;
-
   // Indicates that splice frame generation is enabled.
   const bool splice_frames_enabled_;
 
@@ -444,7 +439,7 @@ class MEDIA_EXPORT ChunkDemuxer : public Demuxer {
   int detected_video_track_count_;
   int detected_text_track_count_;
 
-  std::map<MediaTrack::Id, const DemuxerStream*> track_id_to_demux_stream_map_;
+  std::map<MediaTrack::Id, DemuxerStream*> track_id_to_demux_stream_map_;
 
   DISALLOW_COPY_AND_ASSIGN(ChunkDemuxer);
 };