<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml"
      xmlns:xbl="http://www.mozilla.org/xbl"
      class="reftest-wait">
<head>
  <meta charset="UTF-8" />
  <style>
    children { display:block; }
  </style>
</head>
<body>
    <xbl:children />
    <script>
        onload = function() {
            /* First, schedule a pending restyle of the whole tree. */
            var newSheet = document.createElementNS("http://www.w3.org/1999/xhtml", "style");
            newSheet.appendChild(document.createTextNode("#nosuchelement { }"));
            document.head.appendChild(newSheet);

            /* Now, append a frame to our children element, causing the pending restyle to descend into it. */
            var children = document.getElementsByTagName("xbl:children")[0];
            var span = document.createElementNS("http://www.w3.org/1999/xhtml", "span");
            span.appendChild(document.createTextNode("PASS"));
            children.appendChild(span);
            document.documentElement.removeAttribute("class");
        }
    </script>
</body>
</html>