title: stop all animations in a iframe page
body: <p>Is it possible to stop/resume all animations in a iframe page?</p>
  
  <p>No matter the animations created by js,css3,canvas,create.js,gsap and so on.</p>
  
  <p>I think document.hidden or document.visibilityState can do things like this.</p>
  
  <p>They are read-only,so I tried to dispatch a customer <code>visibilitychange</code> event like this:
  <code>
  iframeDoc.addEventListener('visibilitychange', visibilityChanged,false);
  </code></p>
  
  <p>But it doesn't work.</p>
  
  <p>Can anyone tell me is it possible to stop/resume all animations in frame page?</p>
  
  <p>Thanks very much!</p>