Set the unique_event_id when converting from TouchEvent to WebTouchEvent

ui/events/gesture_detection/motion_event_generic.h

 // Copyright 2014 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 UI_EVENTS_GESTURE_DETECTION_UI_MOTION_EVENT_GENERIC_H_
 #define UI_EVENTS_GESTURE_DETECTION_UI_MOTION_EVENT_GENERIC_H_
 
 #include "base/basictypes.h"
 #include "base/containers/stack_container.h"
 #include "base/memory/scoped_vector.h"
@@ skipping 26 matching lines @@
  public:
   MotionEventGeneric(Action action,
                      base::TimeTicks event_time,
                      const PointerProperties& pointer);
   MotionEventGeneric(const MotionEventGeneric& other);
 
   ~MotionEventGeneric() override;
 
   // MotionEvent implementation.
   int GetId() const override;
+  uint64 GetUniqueEventId() const override;
   Action GetAction() const override;
   int GetActionIndex() const override;
   size_t GetPointerCount() const override;
   int GetPointerId(size_t pointer_index) const override;
   float GetX(size_t pointer_index) const override;
   float GetY(size_t pointer_index) const override;
   float GetRawX(size_t pointer_index) const override;
   float GetRawY(size_t pointer_index) const override;
   float GetTouchMajor(size_t pointer_index) const override;
   float GetTouchMinor(size_t pointer_index) const override;
@@ skipping 24 matching lines @@
     return pointers_[index];
   }
 
   // Add an event to the history. |this| and |event| must have the same pointer
   // count and must both have an action of ACTION_MOVE.
   void PushHistoricalEvent(scoped_ptr<MotionEvent> event);
 
   void set_action(Action action) { action_ = action; }
   void set_event_time(base::TimeTicks event_time) { event_time_ = event_time; }
   void set_id(int id) { id_ = id; }
+  void set_unique_event_id(uint64 unique_event_id) {
+    unique_event_id_ = unique_event_id;
+  }
   void set_action_index(int action_index) { action_index_ = action_index; }
   void set_button_state(int button_state) { button_state_ = button_state; }
   void set_flags(int flags) { flags_ = flags; }
 
   static scoped_ptr<MotionEventGeneric> CloneEvent(const MotionEvent& event);
   static scoped_ptr<MotionEventGeneric> CancelEvent(const MotionEvent& event);
 
  protected:
   MotionEventGeneric();
   MotionEventGeneric(const MotionEvent& event, bool with_history);
   MotionEventGeneric& operator=(const MotionEventGeneric& other);
 
   void PopPointer();
 
  private:
   enum { kTypicalMaxPointerCount = 5 };
 
   Action action_;
   base::TimeTicks event_time_;
   int id_;
+  uint64 unique_event_id_;
   int action_index_;
   int button_state_;
   int flags_;
   base::StackVector<PointerProperties, kTypicalMaxPointerCount> pointers_;
   ScopedVector<MotionEvent> historical_events_;
 };
 
 }  // namespace ui
 
 #endif  // UI_EVENTS_GESTURE_DETECTION_UI_MOTION_EVENT_GENERIC_H_