document-picture-in-picture/copy-document-mode.https.html

<!DOCTYPE html>
<title>Test document picture-in-picture copies Document mode</title>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="/resources/testdriver.js"></script>
<script src="/resources/testdriver-vendor.js"></script>
<body>
<script>
promise_test(async (t) => {
  assert_equals(document.compatMode, "CSS1Compat", "The opener document should not be on quirks mode");
  await test_driver.bless('request PiP window');
  const pipWindow = await documentPictureInPicture.requestWindow();
  assert_equals(pipWindow.document.compatMode, "CSS1Compat", "The picture-in-picture document should not be on quirks mode");
});
</script>
</body>