<!doctype html>
<meta charset="utf-8">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script>
  async_test(t => {
    window.addEventListener('message', t.step_func_done(e => {
      assert_equals(e.data, "can navigate");
    }));
  }, "A => B => B: B should be able to navigate B.");
</script>
<iframe src="https://{{hosts[][www]}}:{{ports[https][0]}}/html/semantics/embedded-content/the-iframe-element/support/iframe-tried-to-be-navigated-by-its-child.html"></iframe>
