ui: Remove some unnecessary functions from the API.

ui/events/events_stub.cc

Index: ui/events/events_stub.cc
diff --git a/ui/events/events_stub.cc b/ui/events/events_stub.cc
index 2ce911361c1843f69e37b3c7ec62502fa1c02705..dbd359660e9649ece932a999602336048e6e2f30 100644
--- a/ui/events/events_stub.cc
+++ b/ui/events/events_stub.cc
@@ -125,20 +125,6 @@ bool GetGestureTimes(const base::NativeEvent& native_event,
   return false;
 }
 
-void SetNaturalScroll(bool enabled) {
-  NOTIMPLEMENTED();
-}
-
-bool IsNaturalScrollEnabled() {
-  NOTIMPLEMENTED();
-  return false;
-}
-
-bool IsTouchpadEvent(const base::NativeEvent& native_event) {
-  NOTIMPLEMENTED();
-  return false;
-}
-
 KeyboardCode KeyboardCodeFromNative(const base::NativeEvent& native_event) {
   NOTIMPLEMENTED();
   return static_cast<KeyboardCode>(0);