Allow MP4 parser to handle multiple audio and video tracks

media/formats/mp4/mp4_stream_parser.h

Index: media/formats/mp4/mp4_stream_parser.h
diff --git a/media/formats/mp4/mp4_stream_parser.h b/media/formats/mp4/mp4_stream_parser.h
index 4e820bff5ebe22f57030a95c6a4c4d0c12d68fbd..1015b98faa648274ffc69f7070263cc6fe4d0a2e 100644
--- a/media/formats/mp4/mp4_stream_parser.h
+++ b/media/formats/mp4/mp4_stream_parser.h
@@ -118,13 +118,12 @@ class MEDIA_EXPORT MP4StreamParser : public StreamParser {
 
   bool has_audio_;
   bool has_video_;
-  uint32_t audio_track_id_;
-  uint32_t video_track_id_;
+  std::set<uint32_t> audio_track_ids_;
+  std::set<uint32_t> video_track_ids_;
   // The object types allowed for audio tracks.
   std::set<int> audio_object_types_;
   bool has_sbr_;
-  bool is_audio_track_encrypted_;
-  bool is_video_track_encrypted_;
+  std::map<uint32_t, bool> is_track_encrypted_;
 
   // Tracks the number of MEDIA_LOGs for skipping top level boxes. Useful to
   // prevent log spam.