chromium/src/third_party/blink/web_tests/external/wpt/client-hints/critical-ch/iframe.https.window.js

// META: script=resources/util.js

async_test((t) => {
  var iframe = document.createElement("iframe");
  iframe.src = ECHO_URL;
  document.body.appendChild(iframe);
  iframe.contentWindow.addEventListener('message', message_listener(t, "FAIL"));
}, "Critical-CH iframe");