Store the id of a contributing motion event in GestureEventData

ui/events/gesture_detection/gesture_provider.h

Index: ui/events/gesture_detection/gesture_provider.h
diff --git a/ui/events/gesture_detection/gesture_provider.h b/ui/events/gesture_detection/gesture_provider.h
index d8542194ccecf19864e1a337354629a2826a9816..421966b3ad84c8fbf84eb97494b66485f954eb08 100644
--- a/ui/events/gesture_detection/gesture_provider.h
+++ b/ui/events/gesture_detection/gesture_provider.h
@@ -84,14 +84,17 @@ class GESTURE_DETECTION_EXPORT GestureProvider {
   bool CanHandle(const MotionEvent& event) const;
 
   void Fling(base::TimeTicks time,
+             int motion_event_id,

[jdduke (slow), 2014/04/03 15:47:54]

Hmm, can we have Fling take a const MotionEvent& arg? Then we can have
EndTouchScrollIfNecessary also take a const MotionEvent& arg.

[tdresser, 2014/04/03 18:09:47]

Done.

              float x,
              float y,
              float velocity_x,
              float velocity_y);
   void Send(const GestureEventData& gesture);
   void SendTapCancelIfNecessary(const MotionEvent& event);
+  void SendTapCancelIfNecessary(const GestureEventData& event);
   bool SendLongTapIfNecessary(const MotionEvent& event);
   void EndTouchScrollIfNecessary(base::TimeTicks time,
+                                 int motion_event_id,
                                  bool send_scroll_end_event);
 
   GestureProviderClient* const client_;