Allow muting/unmuting audio through media track API

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 be941de92d309ee677004e624a5bab79574742a5..009eee61b19f149e2a6b851aa1a39ca5015bfc7f 100644
--- a/media/blink/webmediaplayer_impl.cc
+++ b/media/blink/webmediaplayer_impl.cc
@@ -7,6 +7,7 @@
 #include <algorithm>
 #include <cmath>
 #include <limits>
+#include <sstream>
 #include <string>
 #include <utility>
 
@@ -564,6 +565,45 @@ bool WebMediaPlayerImpl::hasAudio() const {
   return pipeline_metadata_.has_audio;
 }
 
+void WebMediaPlayerImpl::enabledAudioTracksChanged(
+    const blink::WebVector<blink::WebMediaPlayer::TrackId>& enabledTrackIds) {
+  DCHECK(main_task_runner_->BelongsToCurrentThread());
+  CHECK(demuxer_.get());
+
+  std::vector<const DemuxerStream*> enabledAudioStreams;
+  std::stringstream trackIdsStr;
+  for (const auto& trackId : enabledTrackIds) {
+    const DemuxerStream* s = demuxer_->GetDemuxerStreamByTrackId(trackId);
+    CHECK(s);
+    enabledAudioStreams.push_back(s);
+    trackIdsStr << trackId << " ";
+  }
+  MEDIA_LOG(INFO, media_log_)
+      << "WebMediaPlayerImpl::enabledAudioTracksChanged enabledTrackIds="
+      << trackIdsStr.str();
+  pipeline_.OnEnabledAudioStreamsChanged(enabledAudioStreams);
+}
+
+void WebMediaPlayerImpl::selectedVideoTrackChanged(
+    blink::WebMediaPlayer::TrackId* selectedTrackId) {
+  DCHECK(main_task_runner_->BelongsToCurrentThread());
+  CHECK(demuxer_.get());
+
+  const DemuxerStream* selectedVideoStream = nullptr;
+  if (selectedTrackId) {
+    selectedVideoStream = demuxer_->GetDemuxerStreamByTrackId(*selectedTrackId);
+    CHECK(selectedVideoStream);
+    MEDIA_LOG(INFO, media_log_)
+        << "WebMediaPlayerImpl::selectedVideoTrackChanged selectedTrackId="
+        << *selectedTrackId << " selectedVideoStream=" << selectedVideoStream;
+  } else {
+    MEDIA_LOG(INFO, media_log_) << "WebMediaPlayerImpl::"
+                                   "selectedVideoTrackChanged "
+                                   "selectedTrackId=none";
+  }
+  pipeline_.OnSelectedVideoStreamChanged(selectedVideoStream);
+}
+
 blink::WebSize WebMediaPlayerImpl::naturalSize() const {
   DCHECK(main_task_runner_->BelongsToCurrentThread());
 
@@ -827,6 +867,7 @@ void WebMediaPlayerImpl::OnFFmpegMediaTracksUpdated(
   DCHECK(!chunk_demuxer_);
 
   // Report the media track information to blink.
+  std::vector<blink::WebMediaPlayer::TrackId> blinkTrackIds;
   for (const auto& track : tracks->tracks()) {
     if (track->type() == MediaTrack::Audio) {
       auto track_id = client_->addAudioTrack(
@@ -835,7 +876,7 @@ void WebMediaPlayerImpl::OnFFmpegMediaTracksUpdated(
           blink::WebString::fromUTF8(track->label()),
           blink::WebString::fromUTF8(track->language()),
           /*enabled*/ true);
-      (void)track_id;
+      blinkTrackIds.push_back(track_id);
     } else if (track->type() == MediaTrack::Video) {
       auto track_id = client_->addVideoTrack(
           blink::WebString::fromUTF8(track->id()),
@@ -843,12 +884,14 @@ void WebMediaPlayerImpl::OnFFmpegMediaTracksUpdated(
           blink::WebString::fromUTF8(track->label()),
           blink::WebString::fromUTF8(track->language()),
           /*selected*/ true);
-      (void)track_id;
+      blinkTrackIds.push_back(track_id);
     } else {
       // Text tracks are not supported through this code path yet.
       NOTREACHED();
     }
   }
+
+  demuxer_->OnTrackIdsAssigned(*tracks.get(), blinkTrackIds);
 }
 
 void WebMediaPlayerImpl::OnWaitingForDecryptionKey() {