<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<script>

function boom()
{
  var frame = document.createElementNS("http://www.w3.org/1999/xhtml", "iframe");
  document.body.appendChild(frame);
  var frameDoc = frame.contentDocument;
  frameDoc.contentEditable = "true";
  document.body.removeChild(frame);
  SpecialPowers.gc();
  frameDoc.focus();
}

</script>
</head>

<body onload="boom();"></body>
</html>
