Set the target lazily for the coalesced events

third_party/WebKit/Source/core/events/PointerEvent.cpp

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "core/events/PointerEvent.h"
 
 #include "core/dom/Element.h"
 #include "core/events/EventDispatcher.h"
 
 namespace blink {
 
 PointerEvent::PointerEvent(const AtomicString& type,
                            const PointerEventInit& initializer,
                            TimeTicks platform_time_stamp)
     : MouseEvent(type, initializer, platform_time_stamp),
       pointer_id_(0),
       width_(0),
       height_(0),
       pressure_(0),
       tilt_x_(0),
       tilt_y_(0),
       tangential_pressure_(0),
       twist_(0),
-      is_primary_(false) {
+      is_primary_(false),
+      coalesced_events_targets_dirty_(false) {
   if (initializer.hasPointerId())
     pointer_id_ = initializer.pointerId();
   if (initializer.hasWidth())
     width_ = initializer.width();
   if (initializer.hasHeight())
     height_ = initializer.height();
   if (initializer.hasPressure())
     pressure_ = initializer.pressure();
   if (initializer.hasTiltX())
     tilt_x_ = initializer.tiltX();
@@ skipping 18 matching lines @@
 }
 
 bool PointerEvent::IsPointerEvent() const {
   return true;
 }
 
 EventDispatchMediator* PointerEvent::CreateMediator() {
   return PointerEventDispatchMediator::Create(this);
 }
 
-HeapVector<Member<PointerEvent>> PointerEvent::getCoalescedEvents() const {
+void PointerEvent::ReceivedTarget() {
+  coalesced_events_targets_dirty_ = true;
+  MouseEvent::ReceivedTarget();
+}
+
+HeapVector<Member<PointerEvent>> PointerEvent::getCoalescedEvents() {
+  if (coalesced_events_targets_dirty_) {
+    for (auto coalesced_event : coalesced_events_)
+      coalesced_event->SetTarget(target());
+    coalesced_events_targets_dirty_ = false;
+  }
   return coalesced_events_;
 }
 
 DEFINE_TRACE(PointerEvent) {
   visitor->Trace(coalesced_events_);
   MouseEvent::Trace(visitor);
 }
 
 PointerEventDispatchMediator* PointerEventDispatchMediator::Create(
     PointerEvent* pointer_event) {
@@ skipping 15 matching lines @@
 
   DCHECK(!Event().target() || Event().target() != Event().relatedTarget());
 
   Event().GetEventPath().AdjustForRelatedTarget(dispatcher.GetNode(),
                                                 Event().relatedTarget());
 
   return dispatcher.Dispatch();
 }
 
 }  // namespace blink