Get rid of NULLs in core/

core/fxcrt/fx_arabic.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/fxcrt/include/fx_arabic.h"
 #include "core/fxcrt/include/fx_ucd.h"
 
 namespace {
@@ skipping 117 matching lines @@
   if (!pFT || eType >= FX_CHARTYPE_ArabicNormal)
     eType = FX_CHARTYPE_Unknown;
 
   return pFT;
 }
 
 }  // namespace
 
 const FX_ARBFORMTABLE* FX_GetArabicFormTable(FX_WCHAR unicode) {
   if (unicode < 0x622 || unicode > 0x6d5) {
-    return NULL;
+    return nullptr;
   }
   return g_FX_ArabicFormTables + unicode - 0x622;
 }
 FX_WCHAR FX_GetArabicFromAlefTable(FX_WCHAR alef) {
   static const int32_t s_iAlefCount =
       sizeof(gs_FX_AlefTable) / sizeof(FX_ARAALEF);
   for (int32_t iStart = 0; iStart < s_iAlefCount; iStart++) {
     const FX_ARAALEF& v = gs_FX_AlefTable[iStart];
     if (v.wAlef == alef) {
       return v.wIsolated;
@@ skipping 815 matching lines @@
   }
 };
 void FX_BidiLine(CFX_TxtCharArray& chars, int32_t iCount, int32_t iBaseLevel) {
   CFX_BidiLineTemplate<CFX_TxtChar> blt;
   blt.FX_BidiLine(chars, iCount, iBaseLevel);
 }
 void FX_BidiLine(CFX_RTFCharArray& chars, int32_t iCount, int32_t iBaseLevel) {
   CFX_BidiLineTemplate<CFX_RTFChar> blt;
   blt.FX_BidiLine(chars, iCount, iBaseLevel);
 }