Re-enable Eager Gesture Recognition on Aura

ui/events/event.h

Index: ui/events/event.h
diff --git a/ui/events/event.h b/ui/events/event.h
index 56fd74c85d53d17d000fa1b9c6c0796104379056..1960557b9067cd043192cb782720d192a24483d9 100644
--- a/ui/events/event.h
+++ b/ui/events/event.h
@@ -203,6 +203,12 @@ class EVENTS_EXPORT Event {
   // Returns true if the event has a valid |native_event_|.
   bool HasNativeEvent() const;
 
+  // Marks the event as not participating in synchronous gesture recognition.
+  void DisableSynchronousHandling();
+  bool synchronous_handling_disabled() const {
+    return !!(result_ & ER_DISABLE_SYNC_HANDLING);
+  }
+
   // Immediately stops the propagation of the event. This must be called only
   // from an EventHandler during an event-dispatch. Any event handler that may
   // be in the list will not receive the event after this is called.
@@ -488,11 +494,11 @@ class EVENTS_EXPORT TouchEvent : public LocatedEvent {
   TouchEvent(const TouchEvent& model, T* source, T* target)
       : LocatedEvent(model, source, target),
         touch_id_(model.touch_id_),
+        touch_event_id_(model.touch_event_id_),
         radius_x_(model.radius_x_),
         radius_y_(model.radius_y_),
         rotation_angle_(model.rotation_angle_),
-        force_(model.force_) {
-  }
+        force_(model.force_) {}
 
   TouchEvent(EventType type,
              const gfx::PointF& location,
@@ -512,6 +518,7 @@ class EVENTS_EXPORT TouchEvent : public LocatedEvent {
   ~TouchEvent() override;
 
   int touch_id() const { return touch_id_; }
+  int touch_event_id() const { return touch_event_id_; }

[sadrul, 2014/11/27 20:39:30]

touch_id() and touch_event_id() both sound very similar, and so this is a bit
confusing. Add a comment above this explaining the difference.

Perhaps 'unique_id()' would be better than 'touch_event_id()', in the sense that
this should be unique for most reasonable purposes.

[tdresser, 2014/11/28 18:33:37]

Went with unique_event_id, to clarify that it is unique per event, not unique
per pointer or anything like that.
Done.

   float radius_x() const { return radius_x_; }
   float radius_y() const { return radius_y_; }
   float rotation_angle() const { return rotation_angle_; }
@@ -538,10 +545,16 @@ class EVENTS_EXPORT TouchEvent : public LocatedEvent {
   void set_force(float force) { force_ = force; }
 
  private:
+  int get_next_touch_event_id();
+
   // The identity (typically finger) of the touch starting at 0 and incrementing
   // for each separable additional touch that the hardware can detect.
   const int touch_id_;
 
+  // A unique identifier for the touch event. Currently only used for
+  // checking equality of touch events for debugging purposes.
+  const int touch_event_id_;
+
   // Radius of the X (major) axis of the touch ellipse. 0.0 if unknown.
   float radius_x_;