Add layout tests for the audio component of MediaStream Recording.

components/test_runner/mock_web_user_media_client.cc

Index: components/test_runner/mock_web_user_media_client.cc
diff --git a/components/test_runner/mock_web_user_media_client.cc b/components/test_runner/mock_web_user_media_client.cc
index 7cff4c3096df63c2f1ccbac945451b40f0a0915b..3bd55e5f9f626c5aef65da18da0f0a401e6bb67d 100644
--- a/components/test_runner/mock_web_user_media_client.cc
+++ b/components/test_runner/mock_web_user_media_client.cc
@@ -165,7 +165,8 @@ void MockWebUserMediaClient::requestUserMedia(
                       WebVector<WebMediaStreamTrack>());
     stream.setExtraData(new MockExtraData());
 
-    if (request.audio()) {
+    if (request.audio() &&
+        !delegate_->AddMediaStreamAudioSourceAndTrack(&stream)) {
       WebMediaStreamSource source;
       source.initialize("MockAudioDevice#1",
                         WebMediaStreamSource::TypeAudio,
@@ -177,7 +178,8 @@ void MockWebUserMediaClient::requestUserMedia(
       stream.addTrack(web_track);
     }
 
-    if (request.video() && !delegate_->AddMediaStreamSourceAndTrack(&stream)) {
+    if (request.video() &&
+        !delegate_->AddMediaStreamVideoSourceAndTrack(&stream)) {
       WebMediaStreamSource source;
       source.initialize("MockVideoDevice#1",
                         WebMediaStreamSource::TypeVideo,