chromium/third_party/blink/web_tests/svg/custom/textPath-startoffset.svg

<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink" onload="runTest()">
  <path id="thePath" d="M-150 50 L 450 50" />
  <text>
    <textPath id="theTP" xlink:href="#thePath">PASS</textPath>
  </text>
  <script><![CDATA[
    function runTest() {
      var tp = document.getElementById("theTP");
      tp.setAttribute("startOffset", "200");
    }
  ]]></script>
</svg>