Use StreamParser::TrackId instead of string for MediaTrack::byteStreamTrackId

media/filters/ffmpeg_demuxer.cc

 // 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.
 
 #include "media/filters/ffmpeg_demuxer.h"
 
 #include <algorithm>
 #include <memory>
 #include <utility>
 
@@ skipping 1189 matching lines @@
       } else if (codec_type == AVMEDIA_TYPE_VIDEO) {
         MEDIA_LOG(INFO, media_log_)
             << GetDisplayName()
             << ": skipping invalid or unsupported video track";
       }
 
       // This AVStream does not successfully convert.
       continue;
     }
 
-    std::string track_id = base::IntToString(stream->id);
+    StreamParser::TrackId track_id = stream->id;
     std::string track_label = streams_[i]->GetMetadata("handler_name");
     std::string track_language = streams_[i]->GetMetadata("language");
 
     // Some metadata is named differently in FFmpeg for webm files.
     if (strstr(format_context->iformat->name, "webm") ||
         strstr(format_context->iformat->name, "matroska")) {
       // TODO(servolk): FFmpeg doesn't set stream->id correctly for webm files.
       // Need to fix that and use it as track id. crbug.com/323183
-      track_id = base::UintToString(media_tracks->tracks().size() + 1);
+      track_id =
+          static_cast<StreamParser::TrackId>(media_tracks->tracks().size() + 1);
       track_label = streams_[i]->GetMetadata("title");
     }
 
     // Note when we find our audio/video stream (we only want one of each) and
     // record src= playback UMA stats for the stream's decoder config.
     if (codec_type == AVMEDIA_TYPE_AUDIO) {
       CHECK(!audio_stream);
       audio_stream = stream;
       audio_config = streams_[i]->audio_decoder_config();
       RecordAudioCodecStats(audio_config);
@@ skipping 360 matching lines @@
 
 void FFmpegDemuxer::SetLiveness(DemuxerStream::Liveness liveness) {
   DCHECK(task_runner_->BelongsToCurrentThread());
   for (const auto& stream : streams_) {  // |stream| is a ref to a pointer.
     if (stream)
       stream->SetLiveness(liveness);
   }
 }
 
 }  // namespace media