Don't handle NaturalScroll in Chrome but pass it to CMT instead

ui/events/x/events_x.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ui/events/event_constants.h"
 
 #include <cmath>
 #include <string.h>
 #include <X11/extensions/XInput.h>
 #include <X11/extensions/XInput2.h>
@@ skipping 649 matching lines @@
   if (!start_time)
     start_time = &start_time_;
   if (!end_time)
     end_time = &end_time_;
 
   DeviceDataManager::GetInstance()->GetGestureTimes(
       native_event, start_time, end_time);
   return true;
 }
 
-void SetNaturalScroll(bool enabled) {
-  DeviceDataManager::GetInstance()->set_natural_scroll_enabled(enabled);
-}
-
-bool IsNaturalScrollEnabled() {
-  return DeviceDataManager::GetInstance()->natural_scroll_enabled();
-}
-
 bool IsTouchpadEvent(const base::NativeEvent& event) {
   return DeviceDataManager::GetInstance()->IsTouchpadXInputEvent(event);
 }
 
 }  // namespace ui