Get rid of NULLs in xfa/fxbarcode/

xfa/fxbarcode/qrcode/BC_QRAlignmentPatternFinder.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 2007 ZXing authors
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
@@ skipping 87 matching lines @@
           HandlePossibleCenter(stateCount, i, maxJ);
       if (confirmed) {
         return confirmed;
       }
     }
   }
   if (m_possibleCenters.GetSize() != 0) {
     return m_possibleCenters[0]->Clone();
   }
   e = BCExceptionRead;
-  BC_EXCEPTION_CHECK_ReturnValue(e, NULL);
-  return NULL;
+  BC_EXCEPTION_CHECK_ReturnValue(e, nullptr);
+  return nullptr;
 }
 FX_FLOAT CBC_QRAlignmentPatternFinder::CenterFromEnd(
     const CFX_Int32Array& stateCount,
     int32_t end) {
   return (FX_FLOAT)(end - stateCount[2]) - stateCount[1] / 2.0f;
 }
 FX_BOOL CBC_QRAlignmentPatternFinder::FoundPatternCross(
     const CFX_Int32Array& stateCount) {
   FX_FLOAT moduleSize = m_moduleSize;
   FX_FLOAT maxVariance = moduleSize / 2.0f;
@@ skipping 68 matching lines @@
     for (int32_t index = 0; index < max; index++) {
       CBC_QRAlignmentPattern* center = m_possibleCenters[index];
       if (center->AboutEquals(estimatedModuleSize, centerI, centerJ)) {
         return new CBC_QRAlignmentPattern(centerJ, centerI,
                                           estimatedModuleSize);
       }
     }
     m_possibleCenters.Add(
         new CBC_QRAlignmentPattern(centerJ, centerI, estimatedModuleSize));
   }
-  return NULL;
+  return nullptr;
 }