Bookkeep the pointer event listeners added to page

third_party/WebKit/LayoutTests/fast/events/pointerevents/pointer-handler-count.html

+<script src='../../../resources/testharness.js'></script>
+<script src='../../../resources/testharnessreport.js'></script><script>
+
+(function() {
+    var listener = function() { }

[Navid Zolghadr, 2017/06/01 16:26:13]

Can you also add another scenario for testing all possible pointerevent
listeners to make sure we don't miss anyone:

pointerenter
pointerover
pointerleave
pointerout
pointermove
pointerup
pointerdown
pointercancel
gotpointercapture
lostpointercapture

[eirage, 2017/06/01 19:59:24]

Done.

+
+    test(function() {
+
+        assert_equals(window.internals.pointerEventHandlerCount(document), 0);
+        document.addEventListener('pointerenter', listener, true);
+        assert_equals(window.internals.pointerEventHandlerCount(document), 1);
+        document.addEventListener('pointerout', listener, true);
+        assert_equals(window.internals.pointerEventHandlerCount(document), 2);
+        document.addEventListener('pointerenter', listener, false);
+        assert_equals(window.internals.pointerEventHandlerCount(document), 3);
+        document.addEventListener('pointerout', listener, false);
+        assert_equals(window.internals.pointerEventHandlerCount(document), 4);
+        document.removeEventListener('pointerenter', listener, true);
+        assert_equals(window.internals.pointerEventHandlerCount(document), 3);
+        document.removeEventListener('pointerout', listener, true);
+        assert_equals(window.internals.pointerEventHandlerCount(document), 2);
+
+        // Try removing the capturing listener again.
+        document.removeEventListener('pointerenter', listener, true);
+        assert_equals(window.internals.pointerEventHandlerCount(document), 2);
+        document.removeEventListener('pointerout', listener, true);
+        assert_equals(window.internals.pointerEventHandlerCount(document), 2);
+
+        document.removeEventListener('pointerenter', listener, false);
+        assert_equals(window.internals.pointerEventHandlerCount(document), 1);
+        document.removeEventListener('pointerout', listener, false);
+        assert_equals(window.internals.pointerEventHandlerCount(document), 0);
+
+    }, "Test 1: addEventListener/removeEventListener on the document");
+
+})();
+
+(function() {
+    test(function() {
+        assert_equals(window.internals.pointerEventHandlerCount(document), 0);
+        document.onpointerenter = function() { }
+        assert_equals(window.internals.pointerEventHandlerCount(document), 1);
+        document.onpointerenter = function() { }
+        assert_equals(window.internals.pointerEventHandlerCount(document), 1);
+        document.onpointerenter = null;
+        assert_equals(window.internals.pointerEventHandlerCount(document), 0);
+    }, "Test 2: setting onpointerenter on the document");
+})();
+
+(function() {
+    var listener = function() { }
+
+    test(function() {
+        assert_equals(window.internals.pointerEventHandlerCount(document), 0);
+        window.addEventListener('pointerenter', listener, true);
+        assert_equals(window.internals.pointerEventHandlerCount(document), 1);
+        window.addEventListener('pointerout', listener, true);
+        assert_equals(window.internals.pointerEventHandlerCount(document), 2);
+        window.addEventListener('pointerenter', listener, false);
+        assert_equals(window.internals.pointerEventHandlerCount(document), 3);
+        window.addEventListener('pointerout', listener, false);
+        assert_equals(window.internals.pointerEventHandlerCount(document), 4);
+        window.removeEventListener('pointerenter', listener, true);
+        assert_equals(window.internals.pointerEventHandlerCount(document), 3);
+        window.removeEventListener('pointerout', listener, true);
+        assert_equals(window.internals.pointerEventHandlerCount(document), 2);
+
+        // Try removing the capturing listener again.
+        window.removeEventListener('pointerenter', listener, true);
+        assert_equals(window.internals.pointerEventHandlerCount(document), 2);
+        window.removeEventListener('pointerout', listener, true);
+        assert_equals(window.internals.pointerEventHandlerCount(document), 2);
+
+        window.removeEventListener('pointerenter', listener, false);
+        assert_equals(window.internals.pointerEventHandlerCount(document), 1);
+        window.removeEventListener('pointerout', listener, false);
+        assert_equals(window.internals.pointerEventHandlerCount(document), 0);
+    }, "Test 3: addEventListener/removeEventListener on the window");
+})();
+
+(function() {
+    test(function() {
+        assert_equals(window.internals.pointerEventHandlerCount(document), 0);
+        window.onpointerenter = function() { }
+        assert_equals(window.internals.pointerEventHandlerCount(document), 1);
+        window.onpointerenter = function() { }
+        assert_equals(window.internals.pointerEventHandlerCount(document), 1);
+        window.onpointerenter = null;
+        assert_equals(window.internals.pointerEventHandlerCount(document), 0);
+    }, "Test 4: setting onpointerenter on the window");
+})();
+
+</script>
+</body>