<!DOCTYPE html>
<html class="reftest-wait">
<head>
<script>

function boom()
{
  // NB: <script src> is needed to trigger the bug. I'm being clever by also using it to remove reftest-wait.
  var s = "<script src='data:text/javascript,parent.document.documentElement.className=null;'><\/script><svg>";
  document.getElementById("f").contentDocument.write(s);
}

</script>
</head>
<body onload="boom();">
<iframe id="f"></iframe>
</body>
</html>