<!DOCTYPE HTML>
<meta charset=utf-8>
<title>Element Timing: do NOT observe elements from cross-origin iframes</title>
<body>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="resources/element-timing-helpers.js"></script>
<script>
  async_test((t) => {
    assert_implements(window.PerformanceElementTiming, "PerformanceElementTiming is not implemented");
    const observer = new PerformanceObserver(
      t.step_func_done((entryList) => {
        assert_unreached("We should not observe a cross origin element.");
      })
    );
    observer.observe({entryTypes: ['element']});
    // We add the iframe during onload to be sure that the observer is registered
    // in time for it to observe the element timing.
    // TODO(npm): change observer to use buffered flag.
    window.onload = t.step_func(() => {
      // Add a cross origin iframe with an image.
      const iframe = document.createElement('iframe');
      iframe.src = 'http://{{domains[www]}}:{{ports[http][1]}}'
          + '/element-timing/resources/iframe-with-square.html';
      document.body.appendChild(iframe);
      iframe.onload = t.step_func(() => {
        t.step_timeout( () => {
          // After some wait, assume observer did not receive the entry, so the test passes.
          t.done();
        }, 100);
      });
    });
  }, 'Element from cross origin iframe is NOT observable.');
</script>

</body>
