chromium/third_party/blink/web_tests/wpt_internal/scheduler/post-task-detached-scheduler.html

<!doctype html>
<title>Scheduler: postTask to a detached window's scheduler</title>
<link rel="help" href="https://github.com/WICG/scheduling-apis">
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>

<script>
'use strict';

async_test(t => {
  onload = () => {
    let didRun = false;
    const frame = document.body.appendChild(document.createElement('iframe'));
    const frameWindow = frame.contentWindow;
    const controller = new frameWindow.TaskController();
    document.body.removeChild(frame);
    frameWindow.scheduler.postTask(() => { didRun = true; }, {signal: controller.signal});

    t.step_timeout(() => {
      assert_false(didRun, 'The task should not have run.');
      t.done();
    }, 10);
  }
}, 'Test scheduler.postTask() with a scheduler in a detached window');

</script>