client-hints/sandbox/resources/util.js

function sandbox_iframe_test(sandbox, src, title) {
  return promise_test(async t => {
    const iframe = document.createElement("iframe");
    if (sandbox !== "")
      iframe.sandbox = sandbox;
    iframe.src = src;

    let msg = await new Promise(resolve => {
      window.addEventListener('message', resolve);
      document.body.appendChild(iframe);
    });

    assert_equals(msg.data, "PASS", "message from opened frame");
    await fetch("/client-hints/accept-ch-stickiness/resources/clear-site-data.html");
  }, title);
}

function sandbox_popup_listener(src) {
  window.addEventListener('message', e => {
    window.parent.postMessage(e.data, '*');
  });

  let popup_window = window.open("/resources/blank.html");
  popup_window.location.href = src;
}