Set the target lazily for the coalesced events

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

 // 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.
 
 #ifndef PointerEvent_h
 #define PointerEvent_h
 
 #include "core/events/MouseEvent.h"
 #include "core/events/PointerEventInit.h"
 
@@ skipping 22 matching lines @@
   float tangentialPressure() const { return tangential_pressure_; }
   long twist() const { return twist_; }
   const String& pointerType() const { return pointer_type_; }
   bool isPrimary() const { return is_primary_; }
 
   short button() const override { return RawButton(); }
   bool IsMouseEvent() const override;
   bool IsPointerEvent() const override;
 
   EventDispatchMediator* CreateMediator() override;
+  void ReceivedTarget() override;
 
-  HeapVector<Member<PointerEvent>> getCoalescedEvents() const;
+  HeapVector<Member<PointerEvent>> getCoalescedEvents();
 
   DECLARE_VIRTUAL_TRACE();
 
  private:
   PointerEvent(const AtomicString&,
                const PointerEventInit&,
                TimeTicks platform_time_stamp);
 
   int pointer_id_;
   double width_;
   double height_;
   float pressure_;
   long tilt_x_;
   long tilt_y_;
   float tangential_pressure_;
   long twist_;
   String pointer_type_;
   bool is_primary_;
 
+  bool coalesced_events_targets_dirty_;
+
   HeapVector<Member<PointerEvent>> coalesced_events_;
 };
 
 class PointerEventDispatchMediator final : public EventDispatchMediator {
  public:
   static PointerEventDispatchMediator* Create(PointerEvent*);
 
  private:
   explicit PointerEventDispatchMediator(PointerEvent*);
   PointerEvent& Event() const;
   DispatchEventResult DispatchEvent(EventDispatcher&) const override;
 };
 
 DEFINE_EVENT_TYPE_CASTS(PointerEvent);
 
 }  // namespace blink
 
 #endif  // PointerEvent_h