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

chrome/browser/chromeos/system/input_device_settings.cc

Index: chrome/browser/chromeos/system/input_device_settings.cc
diff --git a/chrome/browser/chromeos/system/input_device_settings.cc b/chrome/browser/chromeos/system/input_device_settings.cc
index e92b31adb18df975a0bddb98301537e173da4e85..10cc5a652d387e065261a971da19cd271d510ccf 100644
--- a/chrome/browser/chromeos/system/input_device_settings.cc
+++ b/chrome/browser/chromeos/system/input_device_settings.cc
@@ -151,7 +151,6 @@
   virtual void SetTapToClick(bool enabled) OVERRIDE;
   virtual void SetThreeFingerClick(bool enabled) OVERRIDE;
   virtual void SetTapDragging(bool enabled) OVERRIDE;
-  virtual void SetNaturalScroll(bool enabled) OVERRIDE;
   virtual void MouseExists(const DeviceExistsCallback& callback) OVERRIDE;
   virtual void UpdateMouseSettings(const MouseSettings& update) OVERRIDE;
   virtual void SetMouseSensitivity(int value) OVERRIDE;
@@ -187,12 +186,6 @@
   UpdateTouchpadSettings(settings);
 }
 
-void InputDeviceSettingsImpl::SetNaturalScroll(bool enabled) {
-  TouchpadSettings settings;
-  settings.SetNaturalScroll(enabled);
-  UpdateTouchpadSettings(settings);
-}
-
 void InputDeviceSettingsImpl::SetTapToClick(bool enabled) {
   TouchpadSettings settings;
   settings.SetTapToClick(enabled);
@@ -283,7 +276,6 @@
     tap_to_click_ = other.tap_to_click_;
     three_finger_click_ = other.three_finger_click_;
     tap_dragging_ = other.tap_dragging_;
-    natural_scroll_ = other.natural_scroll_;
   }
   return *this;
 }
@@ -302,14 +294,6 @@
 
 bool TouchpadSettings::GetTapToClick() const {
   return tap_to_click_.value();
-}
-
-void TouchpadSettings::SetNaturalScroll(bool enabled) {
-  natural_scroll_.Set(enabled);
-}
-
-bool TouchpadSettings::GetNaturalScroll() const {
-  return natural_scroll_.value();
 }
 
 void TouchpadSettings::SetThreeFingerClick(bool enabled) {
@@ -354,12 +338,6 @@
     updated = true;
     if (argv)
       AddTPControlArguments("tapdrag", tap_dragging_.value(), argv);
-  }
-  if (natural_scroll_.Update(settings.natural_scroll_)) {
-    updated = true;
-    if (argv)
-      AddTPControlArguments("australian_scrolling", natural_scroll_.value(),
-                            argv);
   }
   return updated;
 }