chromium/third_party/blink/web_tests/external/wpt/html/browsers/the-window-object/support/noreferrer-target.html

<script>
  const channelName = location.search.substr(1),
        channel = new BroadcastChannel(channelName);
  channel.postMessage({ name: window.name,
                        haveOpener: window.opener !== null,
                        referrer: document.referrer });

  // Because messages are not delivered synchronously and because closing a
  // browsing context prompts the eventual clearing of all task sources, this
  // document should not be closed until the opener document has confirmed
  // receipt.
  channel.onmessage = () => window.close();
</script>