Get rid of NULLs in fpdfsdk/

fpdfsdk/include/fsdk_baseform.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 FPDFSDK_INCLUDE_FSDK_BASEFORM_H_
 #define FPDFSDK_INCLUDE_FSDK_BASEFORM_H_
 
 #include <map>
@@ skipping 263 matching lines @@
   CPDFSDK_XFAWidget* GetXFAWidget(CXFA_FFWidget* hWidget);
   void XfaEnableCalculate(FX_BOOL bEnabled);
   FX_BOOL IsXfaCalculateEnabled() const;
   FX_BOOL IsXfaValidationsEnabled();
   void XfaSetValidationsEnabled(FX_BOOL bEnabled);
 #endif  // PDF_ENABLE_XFA
 
   FX_BOOL OnKeyStrokeCommit(CPDF_FormField* pFormField,
                             const CFX_WideString& csValue);
   FX_BOOL OnValidate(CPDF_FormField* pFormField, const CFX_WideString& csValue);
-  void OnCalculate(CPDF_FormField* pFormField = NULL);
+  void OnCalculate(CPDF_FormField* pFormField = nullptr);
   CFX_WideString OnFormat(CPDF_FormField* pFormField, FX_BOOL& bFormated);
 
   void ResetFieldAppearance(CPDF_FormField* pFormField,
                             const FX_WCHAR* sValue,
                             FX_BOOL bValueChanged);
   void UpdateField(CPDF_FormField* pFormField);
 
   FX_BOOL DoAction_Hide(const CPDF_Action& action);
   FX_BOOL DoAction_SubmitForm(const CPDF_Action& action);
   FX_BOOL DoAction_ResetForm(const CPDF_Action& action);
@@ skipping 95 matching lines @@
                                      const CPDFSDK_Annot* p2);
 
   TabOrder m_eTabOrder;
   CPDFSDK_PageView* m_pPageView;
   CFX_ByteString m_sType;
   CFX_ByteString m_sSubType;
   std::vector<CPDFSDK_Annot*> m_Annots;
 };
 
 #endif  // FPDFSDK_INCLUDE_FSDK_BASEFORM_H_