Target touches to the correct display.

ui/events/gestures/gesture_point.h

Index: ui/events/gestures/gesture_point.h
diff --git a/ui/events/gestures/gesture_point.h b/ui/events/gestures/gesture_point.h
index 02aa460859207e96091336d1c7dde55398fff0ec..25ad6feef8aeb7210d7221425efbbee314349ecb 100644
--- a/ui/events/gestures/gesture_point.h
+++ b/ui/events/gestures/gesture_point.h
@@ -79,6 +79,11 @@ class GesturePoint {
 
   const gfx::Rect& enclosing_rectangle() const { return enclosing_rect_; }
 
+  void set_source_device_id(int source_device_id) {
+    source_device_id_ = source_device_id;
+  }
+  int source_device_id() const { return source_device_id_; }
+
  private:
   // Various statistical functions to manipulate gestures.
 
@@ -131,6 +136,8 @@ class GesturePoint {
   // Count of the number of events with same direction.
   gfx::Vector2d same_direction_count_;
 
+  int source_device_id_;
+
   DISALLOW_COPY_AND_ASSIGN(GesturePoint);
 };