<!doctype html>
<meta charset="utf-8">
<title>Check that sandboxed iframe can not navigate their ancestors</title>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script>
  var t = async_test();
  onpopstate = t.unreached_func('no pop state');

  function doNavigation() {
    history.pushState( {state: "one past"}, 'page 2', '');
    frames[0].postMessage('back', '*');
    t.step_timeout(() => {
      t.done();
    }, 1000);
  }
</script>
<iframe id="child_frame" sandbox="allow-scripts" src="support/iframe-tried-to-be-navigated-by-history.html" onload="doNavigation();"></iframe>