Get rid of NULLs in fpdfsdk/

fpdfsdk/formfiller/cffl_combobox.cpp

 // 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
 
 #include "fpdfsdk/formfiller/cffl_combobox.h"
 
 #include "fpdfsdk/formfiller/cba_fontmap.h"
 #include "fpdfsdk/formfiller/cffl_formfiller.h"
 #include "fpdfsdk/formfiller/cffl_iformfiller.h"
 #include "fpdfsdk/include/fsdk_common.h"
 #include "fpdfsdk/include/fsdk_mgr.h"
 #include "fpdfsdk/pdfwindow/PWL_ComboBox.h"
 
 CFFL_ComboBox::CFFL_ComboBox(CPDFDoc_Environment* pApp, CPDFSDK_Annot* pAnnot)
-    : CFFL_FormFiller(pApp, pAnnot), m_pFontMap(NULL) {
+    : CFFL_FormFiller(pApp, pAnnot), m_pFontMap(nullptr) {
   m_State.nIndex = 0;
   m_State.nStart = 0;
   m_State.nEnd = 0;
 }
 
 CFFL_ComboBox::~CFFL_ComboBox() {
   for (const auto& it : m_Maps)
     it.second->InvalidateFocusHandler(this);
   delete m_pFontMap;
 }
@@ skipping 192 matching lines @@
   }
 }
 
 CPWL_Wnd* CFFL_ComboBox::ResetPDFWindow(CPDFSDK_PageView* pPageView,
                                         FX_BOOL bRestoreValue) {
   if (bRestoreValue)
     SaveState(pPageView);
 
   DestroyPDFWindow(pPageView);
 
-  CPWL_Wnd* pRet = NULL;
+  CPWL_Wnd* pRet = nullptr;
 
   if (bRestoreValue) {
     RestoreState(pPageView);
     pRet = GetPDFWindow(pPageView, FALSE);
   } else {
     pRet = GetPDFWindow(pPageView, TRUE);
   }
 
   m_pWidget->UpdateField();
 
@@ skipping 52 matching lines @@
   if (nExport >= 0) {
     if (CPDF_FormField* pFormField = m_pWidget->GetFormField()) {
       swRet = pFormField->GetOptionValue(nExport);
       if (swRet.IsEmpty())
         swRet = pFormField->GetOptionLabel(nExport);
     }
   }
 
   return swRet;
 }