<html class="reftest-wait">
<body>
<div style="position:fixed; width:200px; height:200px; background-color:blue">
    <div style="position:fixed; width:200px; height:200px; left:400px; background-color:red" id="inner"></div>
</div>
</body>
<script>
  function doTest() {
    var d = document.getElementById("inner");
    d.style.backgroundColor = "green";
    document.documentElement.className = "";
  }
  window.addEventListener("MozReftestInvalidate", doTest);
</script>
</html>