title: Can I use service worker with socket-io?
body: <p>I want to push notification to desktop and mobile. For that I following this article: <a href="https://developers.google.com/web/updates/2015/03/push-notifications-on-the-open-web?hl=en" rel="noreferrer">https://developers.google.com/web/updates/2015/03/push-notifications-on-the-open-web?hl=en</a></p>
  
  <p>I have two question:</p>
  
  <ol>
  <li>Can I use push notification to send notification after all tabs are closed (Chrome restart?)</li>
  <li>Can I trigger the notification by using <code>socket.io</code> for example <code>io.on('message')</code> instead of <code>GCM</code>?</li>
  </ol>