<svg xmlns='http://www.w3.org/2000/svg'>
  <defs>
    <linearGradient id='test'>
      <stop id='stop' offset='0' stop-color='red' />
    </linearGradient>
  </defs>
  <rect fill="url(#test)" width='100' height='100' />
  <script>
  <![CDATA[
    if (window.layoutTestController)
      layoutTestController.waitUntilDone();
      var loaded = function() {
        var gradient = document.getElementById("test");
        var stop = document.createElementNS('http://www.w3.org/2000/svg', 'stop');
        stop.setAttribute("offset", "0");
        stop.style.stopColor = 'green';
        gradient.appendChild(stop);
        if (window.layoutTestController)
          layoutTestController.notifyDone();
      }
      window.setTimeout(loaded, 0);
  ]]>
  </script>
</svg>