child_with_static_srcdoc.html | Explore in Territory

<!DOCTYPE html>
<html>
  <head>
    <script>
      window.onmessage = (e) => {
        parent.postMessage(e.data, "*");
      };
    </script>
  </head>
  <body>
    <iframe srcdoc=
    "<p>Grandchild</p><script>onload = () => { parent.postMessage(location.href,'*'); }</script>">
    </iframe>
  </body>
</html>

chromium/third_party/blink/web_tests/external/wpt/html/browsers/browsing-the-web/navigating-across-documents/resources/child_with_static_srcdoc.html