Allow muting/unmuting audio through media track API

media/test/pipeline_integration_test_base.cc

Index: media/test/pipeline_integration_test_base.cc
diff --git a/media/test/pipeline_integration_test_base.cc b/media/test/pipeline_integration_test_base.cc
index 17647ba7ad07dd725c6998ae55f1864f348b398b..9c20aebbf14e788d6e3d38aea9ce8f169af0df7f 100644
--- a/media/test/pipeline_integration_test_base.cc
+++ b/media/test/pipeline_integration_test_base.cc
@@ -83,6 +83,15 @@ void PipelineIntegrationTestBase::DemuxerEncryptedMediaInitDataCB(
 void PipelineIntegrationTestBase::DemuxerMediaTracksUpdatedCB(
     scoped_ptr<MediaTracks> tracks) {
   CHECK(tracks);
+  CHECK(demuxer_);
+
+  // Generate track ids.
+  std::vector<unsigned> track_ids;
+  for (size_t track_id = 1; track_id <= tracks->tracks().size(); ++track_id) {
+    track_ids.push_back(track_id);
+  }
+
+  demuxer_->OnTrackIdsAssigned(*tracks.get(), track_ids);
 }
 
 void PipelineIntegrationTestBase::OnEnded() {
@@ -273,16 +282,14 @@ void PipelineIntegrationTestBase::CreateDemuxer(
     scoped_ptr<DataSource> data_source) {
   data_source_ = std::move(data_source);
 
-  Demuxer::MediaTracksUpdatedCB tracks_updated_cb =
-      base::Bind(&PipelineIntegrationTestBase::DemuxerMediaTracksUpdatedCB,
-                 base::Unretained(this));
-
 #if !defined(MEDIA_DISABLE_FFMPEG)
   demuxer_ = scoped_ptr<Demuxer>(new FFmpegDemuxer(
       message_loop_.task_runner(), data_source_.get(),
       base::Bind(&PipelineIntegrationTestBase::DemuxerEncryptedMediaInitDataCB,
                  base::Unretained(this)),
-      tracks_updated_cb, new MediaLog()));
+      base::Bind(&PipelineIntegrationTestBase::DemuxerMediaTracksUpdatedCB,
+                 base::Unretained(this)),
+      new MediaLog()));
 #endif
 }