MSE: Cleanup WebM tracks parser initialization

media/formats/webm/webm_tracks_parser.h

 // Copyright 2014 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_FORMATS_WEBM_WEBM_TRACKS_PARSER_H_
 #define MEDIA_FORMATS_WEBM_WEBM_TRACKS_PARSER_H_
 
 #include <stdint.h>
 
 #include <map>
@@ skipping 70 matching lines @@
   // Note: Calling media_tracks() method passes the ownership of the MediaTracks
   // object from WebMTracksParser to the caller (which is typically
   // WebMStreamParser object). So this method must be called only once, after
   // track parsing has been completed.
   scoped_ptr<MediaTracks> media_tracks() {
     CHECK(media_tracks_.get());
     return std::move(media_tracks_);
   }
 
  private:
+  void Reset();
+  void ResetTrackEntry();
+
   // WebMParserClient implementation.
   WebMParserClient* OnListStart(int id) override;
   bool OnListEnd(int id) override;
   bool OnUInt(int id, int64_t val) override;
   bool OnFloat(int id, double val) override;
   bool OnBinary(int id, const uint8_t* data, int size) override;
   bool OnString(int id, const std::string& str) override;
 
   int64_t track_type_;
   int64_t track_num_;
@@ skipping 24 matching lines @@
   VideoDecoderConfig video_decoder_config_;
 
   scoped_ptr<MediaTracks> media_tracks_;
 
   DISALLOW_COPY_AND_ASSIGN(WebMTracksParser);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_FORMATS_WEBM_WEBM_TRACKS_PARSER_H_