beforeunload-is-disabled.https.html

<!DOCTYPE html>
<title>Test that onbeforeunload is disabled for document picture in picture</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) => {
      await test_driver.bless('request PiP window from top window');
      const pipWindow = await documentPictureInPicture.requestWindow();
      var onbeforeunloadDisabled = true;
      pipWindow.onbeforeunload = () => {
        onbeforeunloadDisabled = false;
        return "This is a test";
      }
      pipWindow.close();
      assert_true(onbeforeunloadDisabled, 'onbeforeunload should be disabled for document picture in picture');
    });
  </script>
</body>

chromium/third_party/blink/web_tests/external/wpt/document-picture-in-picture/beforeunload-is-disabled.https.html