EventListener-incumbent-global-subframe-1.html

<!DOCTYPE html>
<iframe src="//www2.web-platform.test:8080/dom/resources/EventListener-incumbent-global-subsubframe.html"></iframe>
<script>
  document.domain = "web-platform.test";
  onmessage = function(e) {
    if (e.data == "start") {
      frames[0].document.body.addEventListener("click", frames[0].postMessage.bind(frames[0], "respond", "*", undefined));
      frames[0].postMessage("sendclick", "*");
    } else {
      parent.postMessage(e.data, "*");
    }
  }
</script>

chromium/third_party/blink/web_tests/http/tests/dom/resources/EventListener-incumbent-global-subframe-1.html