feature-policy-fullscreen-relocate.html

<!DOCTYPE html>
<title>Feature-Policy Fullscreen Relocated</title>
<script>
window.onload = function () {
  document.location = "http://localhost:8000/feature-policy/resources/feature-policy-fullscreen.html";
  return new Promise(function(resolve, reject) {
    window.addEventListener('message', function(e) {
      resolve(e.data);
    }, { once: true });
  }).then(function(data) {
    parent.postMessage(data, '*');
  });
}
</script>

chromium/third_party/blink/web_tests/http/tests/feature-policy/resources/feature-policy-fullscreen-relocate.html