<!doctype html>
<meta charset=utf-8>
<title>Check processing of allow attribute in nested browsing context</title>
<link rel="author" title="Google" href="https://www.google.com">
<link rel="help" href="https://html.spec.whatwg.org/multipage/iframe-embed-object.html#attr-iframe-allow">
<link rel="help" href="https://html.spec.whatwg.org/multipage/browsing-the-web.html#initialise-the-document-object">
<link rel="help" href="https://fullscreen.spec.whatwg.org/#fullscreen-enabled-flag">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>

<div id="log"></div>
<script>
  // This returns a data URL (cross-origin with the containing document) which
  // advances a counter, and reports the counter value together with the
  // document's fullscreenEnabled state, every time it receives a postMessage.
  // Fullscreen itself is not important for this test, but the flag is a useful
  // indicator of whether a policy-controlled-feature is allowed or denied.
  function getSourceForCrossOriginPage(initial_count) {
    var page_contents = "<html><body><script>var count="+initial_count+";window.addEventListener('message',function(){parent.postMessage({'count':count++,'fullscreenEnabled':document.fullscreenEnabled},'*');});</scr"+"ipt></body></html>";
    return "data:text/html;base64,"+btoa(page_contents);
  }

  async_test(function(t) {
    var iframe = document.createElement("iframe");
    iframe.src = getSourceForCrossOriginPage(0);

    iframe.addEventListener('load', function() {
      // Request the fullscreenEnabled state whenever the frame loads
      iframe.contentWindow.postMessage(true,"*");
    });

    window.addEventListener('message', this.step_func(function(msg) {
      if (msg.data.count == 0) {
        assert_false(msg.data.fullscreenEnabled, "Document inside cross-origin iframe without allow attribute should not have feature enabled");
        iframe.setAttribute("allow", "fullscreen");
        iframe.contentWindow.postMessage(true,"*"); // Request state again
      } else if (msg.data.count == 1) {
        assert_false(msg.data.fullscreenEnabled, "Feature should be denied when correct allow attribute is added, before reload");
        iframe.src = getSourceForCrossOriginPage(2); // Reload the frame
      } else if (msg.data.count == 2) {
        assert_true(msg.data.fullscreenEnabled, "Feature should be allowed when correct allow attribute is added, after reload");
        iframe.removeAttribute("allow");
        iframe.contentWindow.postMessage(true,"*"); // Request state again
      } else if (msg.data.count == 3) {
        assert_true(msg.data.fullscreenEnabled, "Feature should be allowed when allow attribute is removed, before reload");
        iframe.src = getSourceForCrossOriginPage(4); // Reload the frame
      } else if (msg.data.count == 4) {
        assert_false(msg.data.fullscreenEnabled, "Feature should be denied when allow attribute is removed, after reload");
        iframe.setAttribute("allow", "payment");  // Set allow to an unrelated feature
        iframe.src = getSourceForCrossOriginPage(5); // Reload the frame
      } else if (msg.data.count == 5) {
        assert_false(msg.data.fullscreenEnabled, "Feature should be denied with incorrect allow attribute");
        iframe.setAttribute("allow", "payment;fullscreen");  // Include fullscreen again
        iframe.src = getSourceForCrossOriginPage(6); // Reload the frame
      } else if (msg.data.count == 6) {
        assert_true(msg.data.fullscreenEnabled, "Feature should be allowed with complex allow attribute");
        t.done();
      } else {
        assert_unreached();
      }
    }));

    document.body.appendChild(iframe);
  }, "iframe-cross-origin-allow");

</script>
