Add support for ordinal scroll amounts

ui/base/events/event.h

 // 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.
 
 #ifndef UI_BASE_EVENTS_EVENT_H_
 #define UI_BASE_EVENTS_EVENT_H_
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "base/event_types.h"
@@ skipping 604 matching lines @@
 class UI_EXPORT ScrollEvent : public MouseEvent {
  public:
   explicit ScrollEvent(const base::NativeEvent& native_event);
   template <class T>
   ScrollEvent(const ScrollEvent& model,
               T* source,
               T* target)
       : MouseEvent(model, source, target),
         x_offset_(model.x_offset_),
         y_offset_(model.y_offset_),
+        x_offset_ordinal_(model.x_offset_ordinal_),
+        y_offset_ordinal_(model.y_offset_ordinal_),
         finger_count_(model.finger_count_){
   }
 
   // Used for tests.
   ScrollEvent(EventType type,
               const gfx::Point& location,
               base::TimeDelta time_stamp,
               int flags,
               float x_offset,
               float y_offset,
+              float x_offset_ordinal,
+              float y_offset_ordinal,
               int finger_count);
 
   // Scale the scroll event's offset value.
   // This is useful in the multi-monitor setup where it needs to be scaled
   // to provide a consistent user experience.
   void Scale(const float factor);
 
   float x_offset() const { return x_offset_; }
   float y_offset() const { return y_offset_; }
+  float x_offset_ordinal() const { return x_offset_ordinal_; }
+  float y_offset_ordinal() const { return y_offset_ordinal_; }
   int finger_count() const { return finger_count_; }
 
  private:
+  // Potential accelerated offsets.
   float x_offset_;
   float y_offset_;
+  // Unaccelerated offsets.
+  float x_offset_ordinal_;
+  float y_offset_ordinal_;
+  // Number of fingers on the pad.
   int finger_count_;
 };
 
 class UI_EXPORT GestureEvent : public LocatedEvent {
  public:
   GestureEvent(EventType type,
                int x,
                int y,
                int flags,
                base::TimeDelta time_stamp,
@@ skipping 26 matching lines @@
   // This value is stored as a bitfield because the number of touch ids varies,
   // but we currently don't need more than 32 touches at a time.
   const unsigned int touch_ids_bitfield_;
 
   DISALLOW_COPY_AND_ASSIGN(GestureEvent);
 };
 
 }  // namespace ui
 
 #endif  // UI_BASE_EVENTS_EVENT_H_