chromium/third_party/blink/web_tests/wpt_internal/performance-timeline/performance-user-timing-special-names.html

<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>

<script>
  const kPerformanceMeasureFindExistingName = 4236;
  const kSpecialNameInUserTimingAPI = 'connectStart';
  function clearUseCounter() {
    internals.clearUseCounter(document, kPerformanceMeasureFindExistingName);
  }

  test(t => {
    t.add_cleanup(clearUseCounter);
    assert_false(internals.isUseCounted(document, kPerformanceMeasureFindExistingName), "Performance measure processing special names in User Timing API should not happen");
    performance.mark('curr');
    performance.measure('test-special-names', kSpecialNameInUserTimingAPI, 'curr');
    assert_true(internals.isUseCounted(document, kPerformanceMeasureFindExistingName), "Performance measure processing special names in User Timing API should happen");
  }, 'Performance measure processes special names that are defined in User Timing API');
</script>