[Interop 2023] Make PE/ME enter/leave events non-composed

Chrome always had mouse/pointer enter/leave events as
"composed", which was matching the specs in the past.
However, the specs were updated in the last few years to
make these events non-composed:
  https://github.com/w3c/uievents/pull/210
  https://github.com/w3c/pointerevents/pull/461
Firefox was update too:
https://bugzilla.mozilla.org/show_bug.cgi?id=1484371

This CL makes Chrome spec compliant.

Fixed: 876994, 874082, 1136584
Change-Id: I861b15cd71bc9c06e28d5d325f8b72c72d7cde16
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4536900
Reviewed-by: Mustaq Ahmed <mustaq@chromium.org>
Reviewed-by: Robert Flack <flackr@chromium.org>
Commit-Queue: Mustaq Ahmed <mustaq@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1146033}

third_party/blink/renderer/core/events/pointer_event_factory.cc

@@ -273,8 +273,9 @@ PointerEventInit* PointerEventFactory::ConvertIdTypeButtonsEvent(
 void PointerEventFactory::SetEventSpecificFields(
     PointerEventInit* pointer_event_init,
     const AtomicString& type) {
-  pointer_event_init->setBubbles(type != event_type_names::kPointerenter &&
-                                 type != event_type_names::kPointerleave);
+  bool is_pointer_enter_or_leave = type == event_type_names::kPointerenter ||
+                                   type == event_type_names::kPointerleave;
+  pointer_event_init->setBubbles(!is_pointer_enter_or_leave);
   pointer_event_init->setCancelable(
       type != event_type_names::kPointerenter &&
       type != event_type_names::kPointerleave &&
@@ -282,8 +283,10 @@ void PointerEventFactory::SetEventSpecificFields(
       type != event_type_names::kPointerrawupdate &&
       type != event_type_names::kGotpointercapture &&
       type != event_type_names::kLostpointercapture);
-
-  pointer_event_init->setComposed(true);
+  pointer_event_init->setComposed(
+      RuntimeEnabledFeatures::NonComposedEnterLeaveEventsEnabled()
+          ? !is_pointer_enter_or_leave
+          : true);
   pointer_event_init->setDetail(0);
 }
 

third_party/blink/renderer/core/input/mouse_event_manager.cc

@@ -91,7 +91,10 @@ void SetMouseEventAttributes(MouseEventInit* initializer,
   initializer->setButtons(
       MouseEvent::WebInputEventModifiersToButtons(mouse_event.GetModifiers()));
   initializer->setView(target_node->GetDocument().domWindow());
-  initializer->setComposed(true);
+  initializer->setComposed(
+      RuntimeEnabledFeatures::NonComposedEnterLeaveEventsEnabled()
+          ? !is_mouse_enter_or_leave
+          : true);
   initializer->setDetail(click_count);
   initializer->setRelatedTarget(related_target);
   UIEventWithKeyState::SetFromWebInputEventModifiers(
@@ -996,6 +999,10 @@ bool MouseEventManager::TryStartDrag(
 WebInputEventResult MouseEventManager::DispatchDragSrcEvent(
     const AtomicString& event_type,
     const WebMouseEvent& event) {
+  CHECK(event_type == event_type_names::kDrag ||
+        event_type == event_type_names::kDragend ||
+        event_type == event_type_names::kDragstart);
+
   return DispatchDragEvent(event_type, GetDragState().drag_src_.Get(), nullptr,
                            event, GetDragState().drag_data_transfer_.Get());
 }

third_party/blink/renderer/platform/runtime_enabled_features.json5

@@ -2378,6 +2378,13 @@
       status: "test",
       base_feature: "none",
     },
+    // Makes enter/leave Mouse and Pointer Events non-composed as per
+    // corresponding specifications.
+    {
+      name: "NonComposedEnterLeaveEvents",
+      public: true,
+      status: "experimental",
+    },
     {
       // Kill switch for crbug.com/1427047 fix.
       // TODO(xiaochengh): Remove in M117.

third_party/blink/web_tests/TestExpectations

@@ -3296,15 +3296,6 @@ crbug.com/626703 external/wpt/xhr/event-readystatechange-loaded.any.html [ Failu
 crbug.com/626703 external/wpt/media-source/mediasource-correct-frames-after-reappend.html [ Failure Pass Timeout ]
 crbug.com/626703 external/wpt/media-source/mediasource-correct-frames.html [ Failure Pass Timeout ]
 crbug.com/626703 external/wpt/payment-method-basic-card/steps_for_selecting_the_payment_handler.html [ Timeout ]
-crbug.com/876994 external/wpt/pointerevents/pointerevent_attributes_hoverable_pointers.html?mouse [ Failure ]
-crbug.com/876994 external/wpt/pointerevents/pointerevent_attributes_hoverable_pointers.html?pen [ Failure ]
-crbug.com/876994 external/wpt/pointerevents/pointerevent_attributes_nohover_pointers.html [ Failure ]
-crbug.com/876994 external/wpt/pointerevents/pointerevent_attributes_hoverable_rightbutton.html?mouse [ Failure ]
-crbug.com/876994 external/wpt/pointerevents/pointerevent_attributes_hoverable_rightbutton.html?pen [ Failure ]
-crbug.com/876994 external/wpt/uievents/mouse/attributes.html [ Failure ]
-crbug.com/1136584 external/wpt/pointerevents/capturing_boundary_event_handler_at_ua_shadowdom.html?mouse [ Failure ]
-crbug.com/1136584 external/wpt/pointerevents/capturing_boundary_event_handler_at_ua_shadowdom.html?pen [ Failure ]
-crbug.com/1136584 external/wpt/pointerevents/capturing_boundary_event_handler_at_ua_shadowdom.html?touch [ Failure ]
 crbug.com/626703 external/wpt/payment-method-basic-card/apply_the_modifiers.html [ Timeout ]
 crbug.com/626703 external/wpt/webrtc/RTCPeerConnection-setRemoteDescription-tracks.https.html [ Skip Timeout ]
 crbug.com/626703 external/wpt/webrtc/RTCPeerConnection-remote-track-mute.https.html [ Skip Timeout ]

third_party/blink/web_tests/external/wpt/pointerevents/pointerevent_auxclick_is_a_pointerevent.html

@@ -26,10 +26,15 @@ target.addEventListener("pointerdown", (e)=>{
 
 function testFunction(test){
   return test.step_func(e=>{
-    assert_equals(e.constructor, window.PointerEvent, "auxclick should use a PointerEvent constructor");
-    assert_true(e instanceof PointerEvent, "auxclick should be a PointerEvent");
-    assert_equals(e.pointerId, pointerId, "auxclick's pointerId should match the pointerId of the pointer event that triggers it");
-    assert_equals(e.pointerType, pointerType, "axclick's pointerType should match the pointerType of the pointer event that triggers it");
+    assert_equals(e.constructor, window.PointerEvent,
+        "auxclick should use a PointerEvent constructor");
+    assert_true(e instanceof PointerEvent,
+        "auxclick should be a PointerEvent");
+    assert_equals(e.pointerId, pointerId,
+        "auxclick's pointerId should match the pointerId of the pointer event that triggers it");
+    assert_equals(e.pointerType, pointerType,
+        "auxclick's pointerType should match the pointerType of the pointer event that triggers it");
+    assert_equals(e.composed, true, "auxclick.composed should be true");
   });
 }
 
@@ -51,10 +56,15 @@ function run_test(pointerType){
       .pointerMove(0,0, {origin:target, sourceName:testPointer})
       .pointerDown({button:actions.ButtonType.MIDDLE, sourceName:testPointer})
       .pointerUp({button:actions.ButtonType.MIDDLE, sourceName:testPointer});
-    Promise.all([pointerDownPrevented, eventWatcher.wait_for("auxclick"), actions.send()]).then(()=>resolve());
+    Promise.all([
+      pointerDownPrevented,
+      eventWatcher.wait_for("auxclick"),
+      actions.send()
+    ]).then(()=>resolve());
   }), "auxclick using " + pointerType + " is a PointerEvent");
 }
 
 run_test(inputSource);
-// TODO(crbug.com/1150441): Add test for auxclick from touch.Note: Calling run_test("touch") here times out.
+// TODO(crbug.com/1150441): Add test for auxclick from touch.  Note: Calling
+// run_test("touch") here times out.
 </script>

third_party/blink/web_tests/external/wpt/pointerevents/pointerevent_click_is_a_pointerevent.html

@@ -25,6 +25,7 @@ function assert_click_construction(click_event, window_object) {
       "click should use a PointerEvent constructor");
   assert_true(click_event instanceof window_object.PointerEvent,
       "click should be a PointerEvent instance");
+  assert_equals(click_event.composed, true, "click.composed should be true");
 }
 
 function assert_click_attributes(click_event, pointerdown_event, pointerup_event) {
@@ -36,7 +37,7 @@ function assert_click_attributes(click_event, pointerdown_event, pointerup_event
   assert_equals(click_event.pointerId, pointerup_event.pointerId,
       "click.pointerId should match the pointerId of the triggering pointerup");
   assert_equals(click_event.pointerType, pointerup_event.pointerType,
-                "click.pointerType should match the pointerType of the triggering pointerup");
+      "click.pointerType should match the pointerType of the triggering pointerup");
 }
 
 promise_test(async () => {

third_party/blink/web_tests/external/wpt/pointerevents/pointerevent_contextmenu_is_a_pointerevent.html

@@ -20,10 +20,15 @@ let pointerdownPointerId, pointerdownPointerType;
 let inputSource = location.search.substring(1);
 
 target.addEventListener("contextmenu", contextmenuTest.step_func((e)=>{
-  assert_equals(e.constructor, window.PointerEvent, "contextmenu should use a PointerEvent constructor");
-  assert_true(e instanceof PointerEvent, "contextmenu should be a PointerEvent");
-  assert_equals(e.pointerId, pointerdownPointerId, "contextmenu's pointerId should match the pointerId of the pointer event that triggers it");
-    assert_equals(e.pointerType, pointerdownPointerType, "contextmenu's pointerType should match the pointerType of the pointer event that triggers it");
+  assert_equals(e.constructor, window.PointerEvent,
+      "contextmenu should use a PointerEvent constructor");
+  assert_true(e instanceof PointerEvent,
+      "contextmenu should be a PointerEvent");
+  assert_equals(e.pointerId, pointerdownPointerId,
+      "contextmenu's pointerId should match the pointerId of the pointer event that triggers it");
+  assert_equals(e.pointerType, pointerdownPointerType,
+      "contextmenu's pointerType should match the pointerType of the pointer event that triggers it");
+  assert_equals(e.composed, true, "contextmenu.composed should be true");
 }));
 target.addEventListener("pointerdown", e=>{
   pointerdownPointerId = e.pointerId;

third_party/blink/web_tests/shadow-dom/event-composed-ua.html

@@ -18,15 +18,18 @@ const input2 = document.querySelector('#input2');
 const composedEventTypes = [
   // UI Events
   'blur', 'focus', 'focusin', 'focusout',
-  'click', 'dblclick',
-  'mousedown', 'mouseenter', 'mouseleave', 'mousemove', 'mouseout', 'mouseover', 'mouseup',
+  'dblclick',
   'wheel',
   'beforeinput', 'input',
   'keydown', 'keyup',
   'compositionstart', 'compositionupdate', 'compositionend',
   // Legacy UI Events
   'DOMActivate', 'DOMFocusIn', 'DOMFocusOut', 'keypress',
-  // See LayoutTests/fast/events/touch/basic-single-touch-events.html for Touch Events.
+  // The following events are covered elsewhere in web_tests:
+  // - Mouse Events: wpt/uievents/mouse/attributes.html
+  // - Pointer Events: wpt/pointerevents/pointerevent_*_is_a_pointerevent.html
+  //       and wpt/pointerevents/pointerevent_attributes_*hover*_pointers.html
+  // - Touch Events: fast/events/touch/basic-single-touch-events.html
 ];
 
 promise_test( async (t) => {
@@ -43,9 +46,6 @@ promise_test( async (t) => {
   await mouseClickOn(input.offsetLeft, input.offsetTop);
   await mouseDoubleClickOn(input.offsetLeft, input.offsetTop);
 
-  // For mouseenter/mouseleave
-  await mouseMoveTo(input2.offsetLeft, input2.offsetTop);
-
   input.blur();
   input.focus();
   input.blur();