chromium/third_party/blink/web_tests/svg/custom/rootelement.svg

<?xml version="1.0" encoding="UTF-8"?>
<svg xmlns="http://www.w3.org/2000/svg">
  <rect id="red" width="100" height="100" fill="red" />
  <script type="text/javascript">
  <![CDATA[
    var red = document.getElementById('red');
    var green = document.createElementNS("http://www.w3.org/2000/svg", "rect");
    green.setAttribute("width", "100");
    green.setAttribute("height", "100");
    green.setAttribute("fill", "green");
    red.ownerDocument.rootElement.appendChild(green);
  ]]>
  </script>
</svg>