The Tor Browser / file revision

 <?xml version="1.0"?>

 <?xml-stylesheet href="chrome://global/skin/" type="text/css"?>

 <window xmlns="http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul" onload="boom();">

 <script type="text/javascript">

 function boom()

 {

   var listbox = document.getElementById("listbox");

   listbox.removeChild(listbox.childNodes[1]);

   document.documentElement.style.MozBinding = "url('data:text/xml,%3Cbindings%20xmlns%3D%22http%3A%2F%2Fwww.mozilla.org%2Fxbl%22%3E%3Cbinding%20id%3D%22foo%22%3E%3Ccontent%3E%0A%3Chbox%20xmlns%3D%22http%3A%2F%2Fwww.mozilla.org%2Fkeymaster%2Fgatekeeper%2Fthere.is.only.xul%22%2F%3E%0A%3C%2Fcontent%3E%3C%2Fbinding%3E%3C%2Fbindings%3E%0A')";

   document.documentElement.boxObject.height;

   listbox.removeChild(listbox.childNodes[0]);

 }

 </script>

 <listbox id="listbox" style="-moz-binding: url(data:text/xml,%3Cbindings%20xmlns%3D%22http%3A%2F%2Fwww.mozilla.org%2Fxbl%22%3E%3Cbinding%20id%3D%22foo%22%3E%3Ccontent%3E%0A%3Clistbox%20xmlns%3D%22http%3A%2F%2Fwww.mozilla.org%2Fkeymaster%2Fgatekeeper%2Fthere.is.only.xul%22%3E%3Cchildren%20xmlns%3D%22http%3A%2F%2Fwww.mozilla.org%2Fxbl%22%2F%3E%3C%2Flistbox%3E%0A%3C%2Fcontent%3E%3C%2Fbinding%3E%3C%2Fbindings%3E%0A);"><listitem/><listitem/></listbox>

 </window>