Allow media track switching.

media/blink/webmediaplayer_impl.cc

 // Copyright 2013 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/blink/webmediaplayer_impl.h"
 
 #include <algorithm>
 #include <cmath>
 #include <limits>
 #include <string>
@@ skipping 1003 matching lines @@
       base::saturated_cast<unsigned int>(init_data.size()));
 }
 
 void WebMediaPlayerImpl::OnFFmpegMediaTracksUpdated(
     std::unique_ptr<MediaTracks> tracks) {
   // For MSE/chunk_demuxer case the media track updates are handled by
   // WebSourceBufferImpl.
   DCHECK(demuxer_.get());
   DCHECK(!chunk_demuxer_);
 
-  // Report the media track information to blink.
+  // Report the media track information to blink. Only the first audio track and
+  // the first video track are enabled by default to match blink logic.
+  bool is_first_audio_track = true;
+  bool is_first_video_track = true;
   for (const auto& track : tracks->tracks()) {
     if (track->type() == MediaTrack::Audio) {
       client_->AddAudioTrack(blink::WebString::FromUTF8(track->id()),
                              blink::WebMediaPlayerClient::kAudioTrackKindMain,
                              blink::WebString::FromUTF8(track->label()),
                              blink::WebString::FromUTF8(track->language()),
-                             /*enabled*/ true);
+                             is_first_audio_track);
+      is_first_audio_track = false;
     } else if (track->type() == MediaTrack::Video) {
       client_->AddVideoTrack(blink::WebString::FromUTF8(track->id()),
                              blink::WebMediaPlayerClient::kVideoTrackKindMain,
                              blink::WebString::FromUTF8(track->label()),
                              blink::WebString::FromUTF8(track->language()),
-                             /*selected*/ true);
+                             is_first_video_track);
+      is_first_video_track = false;
     } else {
       // Text tracks are not supported through this code path yet.
       NOTREACHED();
     }
   }
 }
 
 void WebMediaPlayerImpl::SetCdm(blink::WebContentDecryptionModule* cdm) {
   DCHECK(main_task_runner_->BelongsToCurrentThread());
   DCHECK(cdm);
@@ skipping 1277 matching lines @@
 
 void WebMediaPlayerImpl::RecordUnderflowDuration(base::TimeDelta duration) {
   DCHECK(data_source_ || chunk_demuxer_);
   if (data_source_)
     UMA_HISTOGRAM_TIMES("Media.UnderflowDuration", duration);
   else
     UMA_HISTOGRAM_TIMES("Media.UnderflowDuration.MSE", duration);
 }
 
 }  // namespace media