views: Remove dependency on ui::TouchEvent/GestureEvent from views.

ui/views/events/event_aura.cc

Index: ui/views/events/event_aura.cc
diff --git a/ui/views/events/event_aura.cc b/ui/views/events/event_aura.cc
index 7513148b415e5356acbf62b273853d875074dc95..ae3f5ff92605704a83503be41258462d396e500a 100644
--- a/ui/views/events/event_aura.cc
+++ b/ui/views/events/event_aura.cc
@@ -56,9 +56,4 @@ GestureEvent::GestureEvent(const NativeEvent& event)
       details_(static_cast<ui::GestureEventImpl*>(event)->details()) {
 }
 
-int GestureEvent::GetLowestTouchId() const {
-  return native_event() ?  static_cast<ui::GestureEventImpl*>(
-      native_event())->GetLowestTouchId() : 0;
-}
-
 }  // namespace views