Get rid of NULLs in xfa/fxbarcode/

xfa/fxbarcode/oned/BC_OnedCodaBarReader.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
 // Original code is licensed as follows:
 /*
  * Copyright 2008 ZXing authors
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
@@ skipping 130 matching lines @@
   for (int32_t i = rowOffset; i < width; i++) {
     FX_BOOL pixel = row->Get(i);
     if (pixel ^ isWhite) {
       counters[counterPosition]++;
     } else {
       if (counterPosition == patternLength - 1) {
         if (ArrayContains(STARTEND_ENCODING, ToNarrowWidePattern(&counters))) {
           FX_BOOL btemp3 =
               row->IsRange(std::max(0, patternStart - (i - patternStart) / 2),
                            patternStart, FALSE, e);
-          BC_EXCEPTION_CHECK_ReturnValue(e, NULL);
+          BC_EXCEPTION_CHECK_ReturnValue(e, nullptr);
           if (btemp3) {
             CFX_Int32Array* result = new CFX_Int32Array();
             result->SetSize(2);
             (*result)[0] = patternStart;
             (*result)[1] = i;
             return result;
           }
         }
         patternStart += counters[0] + counters[1];
         for (int32_t y = 2; y < patternLength; y++) {
           counters[y - 2] = counters[y];
         }
         counters[patternLength - 2] = 0;
         counters[patternLength - 1] = 0;
         counterPosition--;
       } else {
         counterPosition++;
       }
       counters[counterPosition] = 1;
       isWhite = !isWhite;
     }
   }
   e = BCExceptionNotFound;
-  return NULL;
+  return nullptr;
 }
 FX_BOOL CBC_OnedCodaBarReader::ArrayContains(const FX_CHAR array[],
                                              FX_CHAR key) {
   for (int32_t i = 0; i < 8; i++) {
     if (array[i] == key) {
       return TRUE;
     }
   }
   return FALSE;
 }
@@ skipping 18 matching lines @@
   }
   if ((wideCounters == 2) || (wideCounters == 3)) {
     for (int32_t k = 0; k < 22; k++) {
       if (CHARACTER_ENCODINGS[k] == pattern) {
         return (ALPHABET_STRING)[k];
       }
     }
   }
   return '!';
 }