anchor.diff:      volumeSlider.value = vol;
   
       // Initially play the stream
  -    toggleSound(null);
  +    play();
   
       // Set the volume slider listeners.
       volumeSlider.$elmt.onChange.listen((CustomEvent e) {
  
positive.code:   RangeSlider volumeSlider;
    bool isPlaying;
    AudioElement stream;
  
    MediaBar.created()
      : super.created() {
  
negative.code:     getShadowRoot("media-bar").applyAuthorStyles = true;
  
      toggleSoundButton = $["toggleSound"];
      toggleSoundImage = toggleSoundButton.children.first;
      volumeSlider = new RangeSlider($["volumeSlider"]);
      stream = $["audioElement"];
  
  