<svg xmlns="http://www.w3.org/2000/svg" class="reftest-wait">
<script>
function boom()
{
  var a = document.getElementById("a");
  a.removeAttribute('dur');
  document.documentElement.appendChild(a);
  // Force a sample
  document.documentElement.setCurrentTime(0);
  document.documentElement.removeAttribute("class");
}

window.addEventListener("load", boom, false);
</script>
<animate begin="-2s" dur="2s" id="a"/>
</svg>