<!DOCTYPE html>
<html class="reftest-wait">
  <body>
    <div style="overflow:hidden;height:100px">
      <div style="overflow-x:hidden;position:sticky;top:50px">
        <div id="testdiv" style="width:10px;height:10px;background-color:green"></div>
      </div>
    </div>
  <script>
    function doTest() {
      var x = document.getElementById('testdiv');
      x.style.width = "200px";
      document.documentElement.className = "";
    }
    document.addEventListener("MozReftestInvalidate", doTest, false);
  </script>
  </body>
</html>