 await iframe_load_1;

  const iframe_load_2 = future(iframe, "load");
  iframe.csp = sandbox_policy;
  iframe.src = "about:blank";
  await iframe_load_2;

  const iframe_reply = future(window, "message", iframe);
  iframe.contentDocument.write(check_sandbox_script);
  const result = await iframe_reply;

  assert_equals(result.data, "document-domain-is-disallowed");
}, "about:blank");

promise_test_parallel(async test => {
  const iframe = document.createElement("iframe");
  iframe.csp = sandbox_policy;
  i