Cleanup unneeded FWL theme code.

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 <memory>
 
 #include "xfa/fwl/theme/cfwl_widgettp.h"
 
 class CFWL_MonthCalendarTP : public CFWL_WidgetTP {
  public:
   CFWL_MonthCalendarTP();
   ~CFWL_MonthCalendarTP() override;
 
   // CFWL_WidgetTP
   bool IsValidWidget(IFWL_Widget* pWidget) override;
-  uint32_t SetThemeID(IFWL_Widget* pWidget,
-                      uint32_t dwThemeID,
-                      FX_BOOL bChildren = TRUE) override;
+  uint32_t SetThemeID(IFWL_Widget* pWidget, uint32_t dwThemeID) 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_Error Initialize() override;
   FWL_Error Finalize() override;
 
  protected:
   struct MCThemeData {
     FX_ARGB clrCaption;
@@ skipping 15 matching lines @@
   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);
 
   std::unique_ptr<MCThemeData> m_pThemeData;
   CFX_WideString wsResource;
 };
 
 #endif  // XFA_FWL_THEME_CFWL_MONTHCALENDARTP_H_