Remove unused code.

xfa/fwl/lightwidget/cfwl_scrollbar.h

-// Copyright 2014 PDFium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-// Original code copyright 2014 Foxit Software Inc. http://www.foxitsoftware.com
-
-#ifndef XFA_FWL_LIGHTWIDGET_CFWL_SCROLLBAR_H_
-#define XFA_FWL_LIGHTWIDGET_CFWL_SCROLLBAR_H_
-
-#include "xfa/fwl/lightwidget/cfwl_widget.h"
-
-class CFWL_ScrollBar : public CFWL_Widget {
- public:
-  static CFWL_ScrollBar* Create();
-  FWL_Error Initialize(const CFWL_WidgetProperties* pProperties = NULL);
-  FX_BOOL IsVertical();
-  FWL_Error GetRange(FX_FLOAT& fMin, FX_FLOAT& fMax);
-  FWL_Error SetRange(FX_FLOAT fMin, FX_FLOAT fMax);
-  FX_FLOAT GetPageSize();
-  FWL_Error SetPageSize(FX_FLOAT fPageSize);
-  FX_FLOAT GetStepSize();
-  FWL_Error SetStepSize(FX_FLOAT fStepSize);
-  FX_FLOAT GetPos();
-  FWL_Error SetPos(FX_FLOAT fPos);
-  FX_FLOAT GetTrackPos();
-  FWL_Error SetTrackPos(FX_FLOAT fTrackPos);
-  FX_BOOL DoScroll(uint32_t dwCode, FX_FLOAT fPos = 0.0f);
-  CFWL_ScrollBar();
-  virtual ~CFWL_ScrollBar();
-};
-
-#endif  // XFA_FWL_LIGHTWIDGET_CFWL_SCROLLBAR_H_