ui: Remove some unnecessary functions from the API.

ui/events/win/events_win.cc

Index: ui/events/win/events_win.cc
diff --git a/ui/events/win/events_win.cc b/ui/events/win/events_win.cc
index 9e74d3a4556ff62f17b7ef03d7ec051613d6bbd2..d6b3070c6c5efdddd0281b13ce5052fac298ba09 100644
--- a/ui/events/win/events_win.cc
+++ b/ui/events/win/events_win.cc
@@ -352,20 +352,6 @@ bool GetGestureTimes(const base::NativeEvent& native_event,
   return false;
 }
 
-void SetNaturalScroll(bool enabled) {
-  NOTIMPLEMENTED();
-}
-
-bool IsNaturalScrollEnabled() {
-  NOTIMPLEMENTED();
-  return false;
-}
-
-bool IsTouchpadEvent(const base::NativeEvent& event) {
-  NOTIMPLEMENTED();
-  return false;
-}
-
 int GetModifiersFromACCEL(const ACCEL& accel) {
   int modifiers = EF_NONE;
   if (accel.fVirt & FSHIFT)