chromium/third_party/blink/web_tests/external/wpt/html/browsers/the-window-object/open-close/close_unload.html

<!doctype html>
<title>Running unload handler in window.close()</title>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<div id="log"></div>
<script>
var t = async_test();
var w = window.open("close_unload-1.html");
onmessage = t.step_func(function(event) {
  if (event.data != "loaded") {
    return;
  }
  w.close();
});
callback = function() {t.done()}
</script>