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

function boom()
{
  var frameDoc = document.getElementById("f").contentDocument;
  var elem = frameDoc.documentElement;
  elem.dataset;
  document.adoptNode(elem);
  frameDoc.write("0");
  frameDoc.close();
  document.documentElement.removeAttribute("class");
}

</script>
</head>

<body onload="boom();">
<iframe id="f" src="data:text/html,1"></iframe>
</body>
</html>