title: AngularJS details directive doesn't work on firefox
body: <p>I am using the angularJS 1.3, and found that the  directive doesn't work on firefox 29. Even the test page on the angular site doesn't show the arrow, </p>
  
  <p><a href="https://docs.angularjs.org/api/ng/directive/ngOpen" rel="nofollow">https://docs.angularjs.org/api/ng/directive/ngOpen</a></p>
  
  <p>Any clue on this? Or I have customize to or order to work on FF? </p>
  
  <p>Thanks</p>