chromium/third_party/blink/web_tests/external/wpt/resource-timing/resources/iframe_TAO_match_origin.html

<body>
<script>
function dirname(path) {
    return path.replace(/\/[^\/]*$/, '/');
}

function request() {
  var dirName = dirname(location.href);
  var client = new XMLHttpRequest,
  // create a cross-origin request
    url = dirName.replace('://', '://www.') + 'TAOResponse.py?tao=match_origin';
    client.open("GET", url, false);
    client.send(null);
}

if(window.parent.setup_iframe) {
  window.parent.setup_iframe();
  request();
}
</script>
</body>