Make MouseWheelEvent::UpdateForRootTransform() not scale the mouse wheel offset

ui/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_EVENTS_EVENT_H_
 #define UI_EVENTS_EVENT_H_
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "base/event_types.h"
@@ skipping 455 matching lines @@
                   base::TimeDelta time_stamp,
                   int flags,
                   int changed_button_flags);
 
   // The amount to scroll. This is in multiples of kWheelDelta.
   // Note: x_offset() > 0/y_offset() > 0 means scroll left/up.
   int x_offset() const { return offset_.x(); }
   int y_offset() const { return offset_.y(); }
   const gfx::Vector2d& offset() const { return offset_; }
 
-  // Overridden from LocatedEvent.
-  void UpdateForRootTransform(
-      const gfx::Transform& inverted_root_transform) override;
-
  private:
   gfx::Vector2d offset_;
 };
 
 class EVENTS_EXPORT TouchEvent : public LocatedEvent {
  public:
   explicit TouchEvent(const base::NativeEvent& native_event);
 
   // Create a new TouchEvent which is identical to the provided model.
   // If source / target windows are provided, the model location will be
@@ skipping 393 matching lines @@
 
   const GestureEventDetails& details() const { return details_; }
 
  private:
   GestureEventDetails details_;
 };
 
 }  // namespace ui
 
 #endif  // UI_EVENTS_EVENT_H_