Get rid of NULLs in core/

core/fpdfapi/fpdf_cmaps/fpdf_cmaps.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 "core/fpdfapi/fpdf_cmaps/cmap_int.h"
 
 #include "core/fpdfapi/fpdf_font/font_int.h"
 #include "core/fpdfapi/fpdf_page/cpdf_pagemodule.h"
 #include "core/fpdfapi/include/cpdf_modulemgr.h"
 
 void FPDFAPI_FindEmbeddedCMap(const char* name,
                               int charset,
                               int coding,
                               const FXCMAP_CMap*& pMap) {
-  pMap = NULL;
+  pMap = nullptr;
   CPDF_FontGlobals* pFontGlobals =
       CPDF_ModuleMgr::Get()->GetPageModule()->GetFontGlobals();
   const FXCMAP_CMap* pCMaps =
       pFontGlobals->m_EmbeddedCharsets[charset].m_pMapList;
   for (uint32_t i = 0; i < pFontGlobals->m_EmbeddedCharsets[charset].m_Count;
        i++) {
     if (FXSYS_strcmp(name, pCMaps[i].m_Name))
       continue;
     pMap = &pCMaps[i];
     break;
@@ skipping 154 matching lines @@
 }
 
 void FPDFAPI_LoadCID2UnicodeMap(CIDSet charset,
                                 const uint16_t*& pMap,
                                 uint32_t& count) {
   CPDF_FontGlobals* pFontGlobals =
       CPDF_ModuleMgr::Get()->GetPageModule()->GetFontGlobals();
   pMap = pFontGlobals->m_EmbeddedToUnicodes[charset].m_pMap;
   count = pFontGlobals->m_EmbeddedToUnicodes[charset].m_Count;
 }