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

ui/events/x/device_data_manager.h

 // Copyright 2013 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 UI_EVENTS_X_DEVICE_DATA_MANAGER_H_
 #define UI_EVENTS_X_DEVICE_DATA_MANAGER_H_
 
 // Generically-named #defines from Xlib is conflicting with symbols in GTest.
 // So many tests .cc file #undef Bool before including device_data_manager.h,
 // which makes Bool unrecognized in XInput2.h.
@@ skipping 86 matching lines @@
   // Data struct to store extracted data from an input event.
   typedef std::map<int, double> EventData;
 
   // We use int because enums can be casted to ints but not vice versa.
   static bool IsCMTDataType(const int type);
   static bool IsTouchDataType(const int type);
 
   // Returns the DeviceDataManager singleton.
   static DeviceDataManager* GetInstance();
 
+  // Natural scroll setter/getter.
+  bool natural_scroll_enabled() const { return natural_scroll_enabled_; }
+  void set_natural_scroll_enabled(bool enabled) {
+    natural_scroll_enabled_ = enabled;
+  }
+
   // Returns if XInput2 is available on the system.
   bool IsXInput2Available() const;
 
+  // Get the natural scroll direction multiplier (1.0f or -1.0f).
+  float GetNaturalScrollFactor(int sourceid) const;
+
   // Updates the list of devices.
   void UpdateDeviceList(Display* display);
 
   // For multitouch events we use slot number to distinguish touches from
   // different fingers. This function returns true if the associated slot
   // for |xiev| can be found and it is saved in |slot|, returns false if
   // no slot can be found.
   bool GetSlotNumber(const XIDeviceEvent* xiev, int* slot);
 
   // Get all event data in one pass. We extract only data types that we know
@@ skipping 112 matching lines @@
 
   void InitializeValuatorsForTest(int deviceid,
                                   int start_valuator,
                                   int end_valuator,
                                   double min_value,
                                   double max_value);
 
   static const int kMaxDeviceNum = 128;
   static const int kMaxXIEventType = XI_LASTEVENT + 1;
   static const int kMaxSlotNum = 10;
+  bool natural_scroll_enabled_;
 
   // Major opcode for the XInput extension. Used to identify XInput events.
   int xi_opcode_;
 
   // A quick lookup table for determining if the XI event is an XIDeviceEvent.
   std::bitset<kMaxXIEventType> xi_device_event_types_;
 
   // A quick lookup table for determining if events from the pointer device
   // should be processed.
   std::bitset<kMaxDeviceNum> cmt_devices_;
@@ skipping 29 matching lines @@
 
   unsigned char button_map_[256];
   int button_map_count_;
 
   DISALLOW_COPY_AND_ASSIGN(DeviceDataManager);
 };
 
 }  // namespace ui
 
 #endif  // UI_EVENTS_X_DEVICE_DATA_MANAGER_H_