Convert FWL_ERR into an enum class.

xfa/fwl/theme/cfwl_monthcalendartp.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_THEME_CFWL_MONTHCALENDARTP_H_
 #define XFA_FWL_THEME_CFWL_MONTHCALENDARTP_H_
 
 #include "xfa/fwl/theme/cfwl_widgettp.h"
 
 class CFWL_MonthCalendarTP : public CFWL_WidgetTP {
  public:
   CFWL_MonthCalendarTP();
   ~CFWL_MonthCalendarTP() override;
 
   FX_BOOL IsValidWidget(IFWL_Widget* pWidget) override;
   uint32_t SetThemeID(IFWL_Widget* pWidget,
                       uint32_t dwThemeID,
                       FX_BOOL bChildren = TRUE) override;
   FX_BOOL DrawBackground(CFWL_ThemeBackground* pParams) override;
   FX_BOOL DrawText(CFWL_ThemeText* pParams) override;
   void* GetCapacity(CFWL_ThemePart* pThemePart,
                     CFWL_WidgetCapacity dwCapacity) override;
-  FWL_ERR Initialize() override;
-  FWL_ERR Finalize() override;
+  FWL_Error Initialize() override;
+  FWL_Error Finalize() override;
 
  protected:
   FX_BOOL DrawTotalBK(CFWL_ThemeBackground* pParams, CFX_Matrix* pMatrix);
   FX_BOOL DrawHeadBk(CFWL_ThemeBackground* pParams, CFX_Matrix* pMatrix);
   FX_BOOL DrawLButton(CFWL_ThemeBackground* pParams, CFX_Matrix* pMatrix);
   FX_BOOL DrawRButton(CFWL_ThemeBackground* pParams, CFX_Matrix* pMatrix);
   FX_BOOL DrawDatesInBK(CFWL_ThemeBackground* pParams, CFX_Matrix* pMatrix);
   FX_BOOL DrawDatesInCircle(CFWL_ThemeBackground* pParams, CFX_Matrix* pMatrix);
   FX_BOOL DrawTodayCircle(CFWL_ThemeBackground* pParams, CFX_Matrix* pMatrix);
   FX_BOOL DrawHSeperator(CFWL_ThemeBackground* pParams, CFX_Matrix* pMatrix);
   FX_BOOL DrawWeekNumSep(CFWL_ThemeBackground* pParams, CFX_Matrix* pMatrix);
   FWLTHEME_STATE GetState(uint32_t dwFWLStates);
   void SetThemeData(uint32_t dwThemeID);
   class MCThemeData {
    public:
     FX_ARGB clrCaption;
     FX_ARGB clrSeperator;
     FX_ARGB clrDatesHoverBK;
     FX_ARGB clrDatesSelectedBK;
     FX_ARGB clrDatesCircle;
     FX_ARGB clrToday;
     FX_ARGB clrBK;
   } * m_pThemeData;
   CFX_WideString wsResource;
 };
 
 #endif  // XFA_FWL_THEME_CFWL_MONTHCALENDARTP_H_