chromium/content/test/data/accessibility/html/insert-before.html

<!--
@EXECUTE-AND-WAIT-FOR:moveLastChild()
-->
<img id="a1" alt="a1">
<img id="a2" alt="a2">
<span role="group"><img id="a0" alt="a0"></span>
<script>
  function moveLastChild() {
      document.body.insertBefore(document.querySelector('#a0'),
                                 document.querySelector('#a1'));
      document.title = 'done';
      return 'done';
  }
</script>