fullscreen/api/document-fullscreen-enabled-active-document.html

<!DOCTYPE html>
<title>
    Document#fullscreenEnabled when the document is not the active document
</title>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<div id="log"></div>
<iframe allowfullscreen></iframe>
<script>
    promise_test(async (t) => {
        const iframe = document.querySelector("iframe");
        const documentBeforeNav = iframe.contentDocument;
        await new Promise((resolve) => {
            iframe.onload = resolve;
            iframe.src = "/common/blank.html";
        });
        assert_false(documentBeforeNav.fullscreenEnabled)
    });
</script>