Add support for new scroll valuators coming from CMT

ui/aura/event.h

 // Copyright (c) 2011 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_AURA_EVENT_H_
 #define UI_AURA_EVENT_H_
 #pragma once
 
 #include "base/basictypes.h"
 #include "base/event_types.h"
@@ skipping 186 matching lines @@
  private:
   // Data associated with the drag/drop session.
   const ui::OSExchangeData& data_;
 
   // Bitmask of supported ui::DragDropTypes::DragOperation by the source.
   int source_operations_;
 
   DISALLOW_COPY_AND_ASSIGN(DropTargetEvent);
 };
 
+class AURA_EXPORT ScrollEvent : public MouseEvent {
+ public:
+  ScrollEvent(const base::NativeEvent& native_event);
+  ScrollEvent(const ScrollEvent& model,
+              Window* source,
+              Window* target,
+              ui::EventType type,
+              int flags)
+      : MouseEvent(model, source, target, type, flags),
+        x_offset_(model.x_offset_),
+        y_offset_(model.y_offset_) {
+  }
+
+  float x_offset() const { return x_offset_; }
+  float y_offset() const { return y_offset_; }
+
+ private:
+  float x_offset_;
+  float y_offset_;
+
+  DISALLOW_COPY_AND_ASSIGN(ScrollEvent);
+};
+
 }  // namespace aura
 
 #endif  // UI_AURA_EVENT_H_