chromium/third_party/blink/web_tests/external/wpt/fullscreen/api/element-request-fullscreen-non-top.html

<!DOCTYPE html>
<title>
    Element#requestFullscreen() for non-top element in fullscreen element stack
</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>
<script src="../trusted-click.js"></script>
<div id="log"></div>
<div id="first">
    <div id="last"></div>
</div>
<script>
    promise_test(async (t) => {
        const first = document.getElementById("first");
        const last = document.getElementById("last");

        await Promise.all([trusted_request(first), fullScreenChange()]);
        assert_equals(document.fullscreenElement, first);

        await Promise.all([trusted_request(last), fullScreenChange()]);
        assert_equals(document.fullscreenElement, last);

        await Promise.all([trusted_request(first, last), fullScreenChange()]);
        assert_equals(document.fullscreenElement, first);
    });
</script>