Codebase Browser
chromium
Go to App

chromium/third_party/blink/web_tests/external/wpt/websockets/multi-globals/url-parsing/incumbent/incumbent.html 

<!DOCTYPE html>
<title>Incumbent page used as a test helper</title>

<iframe src="../current/current.html" id="current"></iframe>

<script>
  const current = document.querySelector("#current").contentWindow;

  window.hello = () => {
    window.ws = new current.WebSocket('foo');
    ws.close();
  };
</script>