chromium/third_party/blink/web_tests/fast/events/pointer-use-count.html

<!DOCTYPE HTML>
<script src='../../resources/testharness.js'></script>
<script src='../../resources/testharnessreport.js'></script>
<script src='../../resources/gesture-util.js'></script>

<style>
div.box {
  margin: 5px;
  padding: 20px;
  float: left;
  width: 50px;
  height: 50px;
}
</style>

<body>

<div id="grey" class="box" style="background-color:grey">
</div>

</body>

<script>

var PointerEventAttributeCount = 1321; // Comes from enum Feature in UseCounter.h
var PointerEventAddListenerCount = 1347; // Comes from enum Feature in UseCounter.h
var PointerId = 3866; // Comes from enum WebFeature in web_feature.mojom

promise_test(async () => {

  var targetDiv = document.getElementById("grey");
  var pid = 0;
  var rect = document.getElementById("grey").getBoundingClientRect();
  var x1 = rect.left + 5;
  var y1 = rect.top + 5;

  assert_false(internals.isUseCounted(document, PointerEventAddListenerCount));

  targetDiv.addEventListener("pointerdown", function(event) {
    // Read pointerId to trigger MeasureAs.
    pid = event.pointerId;
  });

  assert_true(internals.isUseCounted(document, PointerEventAddListenerCount));

  assert_false(internals.isUseCounted(document, PointerEventAttributeCount));

  assert_false(internals.isUseCounted(document, PointerId));

  await mouseClickOn(x1, y1);

  await waitUntil( () => { return pid>0; } );

  assert_true(internals.isUseCounted(document, PointerEventAttributeCount));

  assert_true(internals.isUseCounted(document, PointerId));

}, "Verifies that use of pointerEvents is measured by use counters.");

</script>