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

chrome/browser/chromeos/system/fake_input_device_settings.h

 // Copyright 2014 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.
 
 #ifndef CHROME_BROWSER_CHROMEOS_SYSTEM_FAKE_INPUT_DEVICE_SETTINGS_H_
 #define CHROME_BROWSER_CHROMEOS_SYSTEM_FAKE_INPUT_DEVICE_SETTINGS_H_
 
 #include "base/compiler_specific.h"
 #include "base/macros.h"
 #include "chrome/browser/chromeos/system/input_device_settings.h"
@@ skipping 12 matching lines @@
   virtual void UpdateTouchpadSettings(const TouchpadSettings& settings)
       OVERRIDE;
   virtual void SetTouchpadSensitivity(int value) OVERRIDE;
   virtual void SetTapToClick(bool enabled) OVERRIDE;
   virtual void SetThreeFingerClick(bool enabled) OVERRIDE;
   virtual void SetTapDragging(bool enabled) OVERRIDE;
   virtual void MouseExists(const DeviceExistsCallback& callback) OVERRIDE;
   virtual void UpdateMouseSettings(const MouseSettings& settings) OVERRIDE;
   virtual void SetMouseSensitivity(int value) OVERRIDE;
   virtual void SetPrimaryButtonRight(bool right) OVERRIDE;
-  virtual void SetNaturalScroll(bool enabled) OVERRIDE;
-
   virtual bool ForceKeyboardDrivenUINavigation() OVERRIDE;
   virtual void ReapplyTouchpadSettings() OVERRIDE;
   virtual void ReapplyMouseSettings() OVERRIDE;
 
   const TouchpadSettings& current_touchpad_settings() const {
     return current_touchpad_settings_;
   }
 
   const MouseSettings& current_mouse_settings() const {
     return current_mouse_settings_;
   }
 
  private:
   TouchpadSettings current_touchpad_settings_;
   MouseSettings current_mouse_settings_;
 
   DISALLOW_COPY_AND_ASSIGN(FakeInputDeviceSettings);
 };
 
 }  // namespace system
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_SYSTEM_FAKE_INPUT_DEVICE_SETTINGS_H_