MSE: Record counts of detected MSE audio, video and text tracks

media/filters/chunk_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_FILTERS_CHUNK_DEMUXER_H_
 #define MEDIA_FILTERS_CHUNK_DEMUXER_H_
 
 #include <stddef.h>
 #include <stdint.h>
 
@@ skipping 387 matching lines @@
 
   // 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_;
 
+  // Accumulate, by type, detected track counts across the SourceBuffers.
+  int detected_audio_track_count_;
+  int detected_video_track_count_;
+  int detected_text_track_count_;
+
   DISALLOW_COPY_AND_ASSIGN(ChunkDemuxer);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_FILTERS_CHUNK_DEMUXER_H_