fullscreen/api/document-fullscreen-enabled-setting-allowfullscreen.sub.html

<!DOCTYPE html>
<title>Document#fullscreenEnabled setting allowfullscreen after load and then navigating</title>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<div id="log"></div>
<script>
async_test((t) => {
  const iframe = document.createElement('iframe');
  // no allowfullscreen attribute

  let i = 0;

  const path = location.pathname.substring(0, location.pathname.lastIndexOf('/') + 1);
  iframe.src = "http://{{hosts[][]}}:{{ports[http][0]}}" + path + "resources/echo-fullscreenEnabled.html";
  iframe.onload = t.step_func(() => {
    if (i === 0) {
      iframe.allowFullscreen = true;
    }
    iframe.contentWindow.postMessage('What is document.fullscreenEnabled?', '*');
  });

  window.onmessage = t.step_func((e) => {
    i++;
    if (i === 1) {
      assert_false(e.data, 'document.fullscreenEnabled in the iframe, before navigation');

      // Navigate the iframe. This will fire a second 'load' event on the iframe.
      iframe.contentWindow.location.href = iframe.src + '?2';
    } else {
      assert_true(e.data, 'document.fullscreenEnabled in the iframe, after navigation');
      t.done();
    }
  });

  document.body.appendChild(iframe);
});
</script>