history-traversal-navigates-multiple-frames.html

<!doctype html>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<iframe id="i" src="/common/blank.html"></iframe>
<script>
async_test(t => {
  window.onload = () => t.step_timeout(t.step_func(() => {
    let starting_history_length = history.length;
    location.hash = "#a";
    assert_equals(starting_history_length + 1, history.length);
    i.contentWindow.location.hash = "#b";
    assert_equals(starting_history_length + 2, history.length);

    let popstateCount = 0;
    const popstateCalled = t.step_func(() => {
      popstateCount++;
      if (popstateCount < 2)
        return;
      assert_equals(location.hash, "");
      assert_equals(i.contentWindow.location.hash, "");
      t.done();
    });

    window.onpopstate = popstateCalled;
    i.contentWindow.onpopstate = popstateCalled;
    history.go(-2);
  }), 0);
}, "A history traversal should be able to navigate a parent and child simultaneously");
</script>

chromium/third_party/blink/web_tests/external/wpt/html/browsers/browsing-the-web/history-traversal/history-traversal-navigates-multiple-frames.html