Unify media track info reporting on a demuxer level

media/blink/webmediaplayer_impl.cc

Index: media/blink/webmediaplayer_impl.cc
diff --git a/media/blink/webmediaplayer_impl.cc b/media/blink/webmediaplayer_impl.cc
index 408569c7560234a179ccfed3ed0b766ce0bf3aaf..3e359cbfb0a4c5f86e8eb27847df4e335ad5dc7f 100644
--- a/media/blink/webmediaplayer_impl.cc
+++ b/media/blink/webmediaplayer_impl.cc
@@ -848,6 +848,14 @@ void WebMediaPlayerImpl::OnEncryptedMediaInitData(
       base::saturated_cast<unsigned int>(init_data.size()));
 }
 
+void WebMediaPlayerImpl::OnFFmpegMediaTracksUpdated(
+    scoped_ptr<MediaTracks> tracks) {
+  // For MSE/chunk_demuxer case the media track updates are handled by
+  // WebSourceBufferImpl.
+  DCHECK(demuxer_.get());
+  DCHECK(!chunk_demuxer_);
+}
+
 void WebMediaPlayerImpl::OnWaitingForDecryptionKey() {
   encrypted_client_->didBlockPlaybackWaitingForKey();
 
@@ -1383,8 +1391,13 @@ void WebMediaPlayerImpl::StartPipeline() {
     DCHECK(data_source_);
 
 #if !defined(MEDIA_DISABLE_FFMPEG)
+    Demuxer::MediaTracksUpdatedCB media_tracks_updated_cb =
+        base::Bind(&WebMediaPlayerImpl::OnFFmpegMediaTracksUpdated,
+                   base::Unretained(this));
+
     demuxer_.reset(new FFmpegDemuxer(media_task_runner_, data_source_.get(),
-                                     encrypted_media_init_data_cb, media_log_));
+                                     encrypted_media_init_data_cb,
+                                     media_tracks_updated_cb, media_log_));
 #else
     OnPipelineError(PipelineStatus::DEMUXER_ERROR_COULD_NOT_OPEN);
     return;