<!DOCTYPE HTML>
<meta charset=utf-8>
<head>
<title>Largest Contentful Paint: do NOT observe elements from same-origin iframes</title>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
</head>
<body>
<script>
  async_test((t) => {
    assert_implements(window.LargestContentfulPaint, "LargestContentfulPaint is not implemented");
    const observer = new PerformanceObserver(
      t.step_func_done(entryList => {
        assert_unreached("Should not have received an entry!");
      })
    );
    observer.observe({type: 'largest-contentful-paint', buffered: true});
    // After a delay, assume that no entry was produced.
    t.step_timeout(() => {
      t.done();
    }, 200);
  }, 'Element in child iframe is not observed, even if same-origin.');
</script>
<iframe src='resources/iframe-with-content.html'></iframe>
</body>
