Attempt to fix some -Woverloaded-virtual warnings.

fpdfsdk/include/pdfwindow/PWL_SpecialButton.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 _PWL_SPECIALBUTTON_H_
 #define _PWL_SPECIALBUTTON_H_
 
 #if _MSC_VER > 1000
@@ skipping 12 matching lines @@
 };
 
 class PWL_CLASS CPWL_CheckBox : public CPWL_Button
 {
 public:
         CPWL_CheckBox();
         virtual ~CPWL_CheckBox();
 
 public:
         virtual CFX_ByteString          GetClassName() const;
-        virtual FX_BOOL                         OnLButtonUp(const CPDF_Point & point);
-        virtual FX_BOOL                         OnChar(FX_WORD nChar);
+        virtual FX_BOOL                         OnLButtonUp(const CPDF_Point & point, FX_DWORD nFlag);
+        virtual FX_BOOL                         OnChar(FX_WORD nChar, FX_DWORD nFlag);
 
         void                                            SetCheck(FX_BOOL bCheck);
         FX_BOOL                                         IsChecked() const;
 
 private:
         FX_BOOL                                         m_bChecked;
 };
 
 class PWL_CLASS CPWL_RadioButton : public CPWL_Button
 {
 public:
         CPWL_RadioButton();
         virtual ~CPWL_RadioButton();
 
 public:
         virtual CFX_ByteString          GetClassName() const;
-        virtual FX_BOOL                         OnLButtonUp(const CPDF_Point & point);
-        virtual FX_BOOL                         OnChar(FX_WORD nChar);
+        virtual FX_BOOL                         OnLButtonUp(const CPDF_Point & point, FX_DWORD nFlag);
+        virtual FX_BOOL                         OnChar(FX_WORD nChar, FX_DWORD nFlag);
 
         void                                            SetCheck(FX_BOOL bCheck);
         FX_BOOL                                         IsChecked() const;
 
 private:
         FX_BOOL                                         m_bChecked;
 };
 
 #endif