chromium/third_party/blink/web_tests/external/wpt/event-timing/modal-dialog-interrupt-paint.html

<!DOCTYPE html>
<html>
<meta charset=utf-8 />
<title>Event Timing: Modal Dialog Interrupt Paint</title>
<button id='testButtonId'>Click me.</button>
<script src=/resources/testharness.js></script>
<script src=/resources/testharnessreport.js></script>
<script src=/resources/testdriver.js></script>
<script src=/resources/testdriver-actions.js></script>
<script src=/resources/testdriver-vendor.js></script>
<script src=resources/event-timing-test-utils.js></script>

<script>
  let observedEntries = [];
  const map = new Map();
  const events = ['click'];
  const showModalDialog = () => {
    alert();
  };
  document.getElementById('testButtonId').addEventListener("click", showModalDialog);

  promise_test(async t => {
    assert_implements(window.PerformanceEventTiming, 'Event Timing is not supported.');

    const callback = (entryList) => { observedEntries = observedEntries.concat(entryList.getEntries().filter(filterAndAddToMap(events, map))); };
    const readyToResolve = () => { return observedEntries.length >= 1; };
    const observerPromise = createPerformanceObserverPromise(['event'], callback, readyToResolve);

    await interactAndObserve('click', document.getElementById('testButtonId'), observerPromise);

    const clickEntry = observedEntries[0];
    assert_less_than(clickEntry.startTime + clickEntry.duration, clickEntry.processingEnd, 'Event duration measurement should stop at the modal dialog showing time, which should be before processingEnd.');
    assert_greater_than(clickEntry.interactionId, 0, 'Should have a non-trivial interactionId for click event');
  }, "Event Timing: showing modal dialogs is an alternative end point.");

</script>

</html>