Get rid of NULLs in xfa/fxbarcode/

xfa/fxbarcode/qrcode/BC_QRCodeWriter.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 39 matching lines @@
     return FALSE;
   }
   m_iCorrectLevel = level;
   return TRUE;
 }
 uint8_t* CBC_QRCodeWriter::Encode(const CFX_WideString& contents,
                                   int32_t ecLevel,
                                   int32_t& outWidth,
                                   int32_t& outHeight,
                                   int32_t& e) {
-  CBC_QRCoderErrorCorrectionLevel* ec = NULL;
+  CBC_QRCoderErrorCorrectionLevel* ec = nullptr;
   switch (ecLevel) {
     case 0:
       ec = CBC_QRCoderErrorCorrectionLevel::L;
       break;
     case 1:
       ec = CBC_QRCoderErrorCorrectionLevel::M;
       break;
     case 2:
       ec = CBC_QRCoderErrorCorrectionLevel::Q;
       break;
     case 3:
       ec = CBC_QRCoderErrorCorrectionLevel::H;
       break;
     default: {
       e = BCExceptionUnSupportEclevel;
-      BC_EXCEPTION_CHECK_ReturnValue(e, NULL);
+      BC_EXCEPTION_CHECK_ReturnValue(e, nullptr);
     }
   }
   CBC_QRCoder qr;
   if (m_iVersion > 0 && m_iVersion < 41) {
     CFX_ByteString byteStr = contents.UTF8Encode();
     CBC_QRCoderEncoder::Encode(byteStr, ec, &qr, e, m_iVersion);
   } else {
     CBC_QRCoderEncoder::Encode(contents, ec, &qr, e);
   }
-  BC_EXCEPTION_CHECK_ReturnValue(e, NULL);
+  BC_EXCEPTION_CHECK_ReturnValue(e, nullptr);
   outWidth = qr.GetMatrixWidth();
   outHeight = qr.GetMatrixWidth();
   uint8_t* result = FX_Alloc2D(uint8_t, outWidth, outHeight);
   FXSYS_memcpy(result, qr.GetMatrix()->GetArray(), outWidth * outHeight);
   return result;
 }
 uint8_t* CBC_QRCodeWriter::Encode(const CFX_ByteString& contents,
                                   BCFORMAT format,
                                   int32_t& outWidth,
                                   int32_t& outHeight,
                                   int32_t hints,
                                   int32_t& e) {
-  return NULL;
+  return nullptr;
 }
 uint8_t* CBC_QRCodeWriter::Encode(const CFX_ByteString& contents,
                                   BCFORMAT format,
                                   int32_t& outWidth,
                                   int32_t& outHeight,
                                   int32_t& e) {
-  return NULL;
+  return nullptr;
 }