use unique_ptr in xfa_checksum.h

xfa/fxfa/xfa_checksum.h

 // 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
 
 #ifndef XFA_FXFA_XFA_CHECKSUM_H_
 #define XFA_FXFA_XFA_CHECKSUM_H_
 
+#include <memory>
+
 #include "core/fdrm/crypto/fx_crypt.h"
 #include "xfa/fde/xml/cfx_saxreader.h"
 #include "xfa/fxfa/fxfa.h"
 
 class CXFA_SAXReaderHandler;
 class CXFA_ChecksumContext;
 
 class CXFA_SAXContext {
  public:
   CXFA_SAXContext() : m_eNode(CFX_SAXItem::Type::Unknown) {}
@@ skipping 43 matching lines @@
 
   void StartChecksum();
   void Update(const CFX_ByteStringC& bsText);
   bool UpdateChecksum(const CFX_RetainPtr<IFX_SeekableReadStream>& pSrcFile,
                       FX_FILESIZE offset = 0,
                       size_t size = 0);
   void FinishChecksum();
   CFX_ByteString GetChecksum() const;
 
  protected:
-  CFX_SAXReader* m_pSAXReader;
-  CRYPT_sha1_context* m_pByteContext;
+  std::unique_ptr<CFX_SAXReader> m_pSAXReader;
+  std::unique_ptr<CRYPT_sha1_context> m_pByteContext;
   CFX_ByteString m_bsChecksum;
 };
 
 #endif  // XFA_FXFA_XFA_CHECKSUM_H_