Convert FWL_ERR into an enum class.

xfa/fwl/core/ifwl_themeprovider.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_CORE_IFWL_THEMEPROVIDER_H_
 #define XFA_FWL_CORE_IFWL_THEMEPROVIDER_H_
 
 #include "core/fxcrt/include/fx_coordinates.h"
 #include "core/fxcrt/include/fx_system.h"
 #include "xfa/fwl/core/fwl_error.h"
 #include "xfa/fwl/theme/cfwl_widgettp.h"
 
 class CFWL_ThemeBackground;
 class CFWL_ThemePart;
 class CFWL_ThemeText;
 class IFWL_Widget;
 
 class IFWL_ThemeProvider {
  public:
   virtual ~IFWL_ThemeProvider() {}
   virtual FX_BOOL IsValidWidget(IFWL_Widget* pWidget) = 0;
   virtual uint32_t GetThemeID(IFWL_Widget* pWidget) = 0;
   virtual uint32_t SetThemeID(IFWL_Widget* pWidget,
                               uint32_t dwThemeID,
                               FX_BOOL bChildren = TRUE) = 0;
-  virtual FWL_ERR GetThemeMatrix(IFWL_Widget* pWidget, CFX_Matrix& matrix) = 0;
-  virtual FWL_ERR SetThemeMatrix(IFWL_Widget* pWidget,
-                                 const CFX_Matrix& matrix) = 0;
+  virtual FWL_Error GetThemeMatrix(IFWL_Widget* pWidget,
+                                   CFX_Matrix& matrix) = 0;
+  virtual FWL_Error SetThemeMatrix(IFWL_Widget* pWidget,
+                                   const CFX_Matrix& matrix) = 0;
   virtual FX_BOOL DrawBackground(CFWL_ThemeBackground* pParams) = 0;
   virtual FX_BOOL DrawText(CFWL_ThemeText* pParams) = 0;
   virtual void* GetCapacity(CFWL_ThemePart* pThemePart,
                             CFWL_WidgetCapacity dwCapacity) = 0;
   virtual FX_BOOL IsCustomizedLayout(IFWL_Widget* pWidget) = 0;
-  virtual FWL_ERR GetPartRect(CFWL_ThemePart* pThemePart,
-                              CFX_RectF& rtPart) = 0;
+  virtual FWL_Error GetPartRect(CFWL_ThemePart* pThemePart,
+                                CFX_RectF& rtPart) = 0;
   virtual FX_BOOL IsInPart(CFWL_ThemePart* pThemePart,
                            FX_FLOAT fx,
                            FX_FLOAT fy) = 0;
   virtual FX_BOOL CalcTextRect(CFWL_ThemeText* pParams, CFX_RectF& rect) = 0;
 };
 
 #endif  // XFA_FWL_CORE_IFWL_THEMEPROVIDER_H_