chromium/third_party/blink/web_tests/external/wpt/referrer-policy/generic/iframe-src-change.html

<!DOCTYPE html>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<body>
<script>
function nextMessage() {
  return new Promise((resolve, reject) => {
    window.addEventListener('message', e => resolve(e.data), {once: true});
  });
}

promise_test(async () => {
  let iframe = document.createElement('iframe');
  iframe.setAttribute('src', '/common/security-features/subresource/document.py?first')
  iframe.setAttribute('referrerpolicy', 'no-referrer');
  document.body.appendChild(iframe);

  try {
    {
      let {referrer: documentReferrer, headers: {referer: httpReferrer}} = await nextMessage();
      assert_equals(httpReferrer, undefined, 'expected no HTTP Referer header on initial load');
      assert_equals(documentReferrer, undefined, 'expected no document.referrer on initial load');
    }

    iframe.setAttribute('src', '/common/security-features/subresource/document.py?second');

    {
      let {referrer: documentReferrer, headers: {referer: httpReferrer}} = await nextMessage();
      assert_equals(httpReferrer, undefined, 'expected no HTTP Referer header on src change');
      assert_equals(documentReferrer, undefined, 'expected no document.referrer on src change');
    }
  } finally {
    iframe.remove();
  }
}, "Checks that referrerpolicy is respected when an iframe's src changes.");
</script>
</body>