chromium/third_party/blink/web_tests/external/wpt/html/browsers/browsing-the-web/unloading-documents/unload/007.html

<!doctype html>
<title>salvagable state of document after setting unload listener</title>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<div id="log"></div>
<script>
var t = async_test();

var loaded = false;
var unload_fired = false;
var timeout_fired = false;

function start_test() {
  step_timeout(t.step_func(function() {
                             assert_true(unload_fired);
                             assert_false(timeout_fired);
                             t.done()
                         }), 1000);
}

onload = function() {setTimeout(function() {
  var iframe = document.getElementsByTagName("iframe")[0]
  onload = null;
  iframe.src="007-1.html?" + Math.random();
}, 100)};

</script>
<iframe></iframe>