<!DOCTYPE HTML>
<meta charset=utf-8>
<title>LongTask Timing: long task in nested child iframe</title>
<body>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="resources/utils.js"></script>
<h1>Long Tasks with detached iframe</h1>
<div id="log"></div>
<script>
promise_test(async t => {
assert_implements(window.PerformanceLongTaskTiming, 'Longtasks are not supported.');
const iframe = document.createElement("iframe");
document.body.appendChild(iframe);
t.add_cleanup(() => iframe.remove());
t.step_timeout(() => {
busyWait();
iframe.remove();
});
}, 'Performance longtask entries dont crash when a frame is detached.');
</script>
</body>