title: Chromecast event for device disconnect (sender)
body: <p>Is there event that will notify a sender app when the use selects "stop cast" from within the chrome extension?</p>
  
  <p>I've a chrome sender app get's in a limbo state if the user chooses to stop the cast from the extension instead of the app cast button.</p>
  
  <p>EDIT:
  This is some relevant code:</p>
  
  <pre><code>CastPlayer.prototype.onMediaDiscovered = function (how, mediaSession) {
    this.currentMediaSession = mediaSession;
    // ...    
    this.currentMediaSession.addUpdateListener(this.onMediaStatusUpdate.bind(this));
    // ...
  };
  
  CastPlayer.prototype.onMediaStatusUpdate = function (e) {
    console.log(e);
  };
  </code></pre>