Get rid of NULLs in fpdfsdk/

fpdfsdk/formfiller/cffl_listbox.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_listbox.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_ListBox.h"
 
 #define FFL_DEFAULTLISTBOXFONTSIZE 12.0f
 
 CFFL_ListBox::CFFL_ListBox(CPDFDoc_Environment* pApp, CPDFSDK_Annot* pWidget)
-    : CFFL_FormFiller(pApp, pWidget), m_pFontMap(NULL) {}
+    : CFFL_FormFiller(pApp, pWidget), m_pFontMap(nullptr) {}
 
 CFFL_ListBox::~CFFL_ListBox() {
   delete m_pFontMap;
 }
 
 PWL_CREATEPARAM CFFL_ListBox::GetCreateParam() {
   PWL_CREATEPARAM cp = CFFL_FormFiller::GetCreateParam();
 
   uint32_t dwFieldFlag = m_pWidget->GetFieldFlags();
 
@@ skipping 156 matching lines @@
   }
 }
 
 CPWL_Wnd* CFFL_ListBox::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();
 
   return pRet;
 }