mozilla-release/testing/web-platform/tests/fullscreen/api/element-ready-check-not-allowed-manual.html

<!DOCTYPE html>
<title>Element ready check with enabled flag not set</title>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="../trusted-click.js"></script>
<div id="log"></div>
<iframe></iframe>
<script>
// wait for load event to avoid https://bugzil.la/1493878
window.onload = function() {
  async_test(function(t) {
      var iframe = document.querySelector("iframe");
      document.onfullscreenchange = t.unreached_func("document fullscreenchange event");
      document.onfullscreenerror = t.unreached_func("document fullscreenerror event");
      iframe.contentDocument.onfullscreenchange = t.unreached_func("iframe fullscreenchange event");
      iframe.contentDocument.onfullscreenerror = t.step_func_done();
      assert_false(iframe.contentDocument.fullscreenEnabled, "fullscreen enabled flag");
      trusted_request(t, iframe.contentDocument.body, document.body);
  });
};
</script>