Backout bug 1190040 for test failures

dom/html/HTMLMediaElement.cpp

@@ -4509,11 +4509,6 @@ void HTMLMediaElement::UpdateAudioChannelPlayingState()
 void
 HTMLMediaElement::NotifyAudioChannelAgent(bool aPlaying)
 {
-  // Don't do anything if this element doesn't have any audio tracks.
-  if (!HasAudio()) {
-    return;
-  }
-
   // Immediately check if this should go to the MSG instead of the normal
   // media playback route.
   WindowAudioCaptureChanged();