Merge to XFA: Disable JBIG2 cache; prevent data corruption - try 2.

core/src/fxcodec/jbig2/JBig2_SymbolDict.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 _JBIG2_SYMBOL_DICT_H_
-#define _JBIG2_SYMBOL_DICT_H_
+#ifndef CORE_SRC_FXCODEC_JBIG2_JBIG2_SYMBOLDICT_H_
+#define CORE_SRC_FXCODEC_JBIG2_JBIG2_SYMBOLDICT_H_
 
+#include "../../../../third_party/base/nonstd_unique_ptr.h"
+#include "../../../include/fxcrt/fx_basic.h"
 #include "JBig2_ArithDecoder.h"
-#include "JBig2_Define.h"
-#include "JBig2_Image.h"
+
+class CJBig2_Image;
 
 class CJBig2_SymbolDict {
  public:
   CJBig2_SymbolDict();
-  CJBig2_SymbolDict* DeepCopy();
   ~CJBig2_SymbolDict();
 
+  nonstd::unique_ptr<CJBig2_SymbolDict> DeepCopy() const;
+
  public:
   FX_DWORD SDNUMEXSYMS;
   CJBig2_Image** SDEXSYMS;
   FX_BOOL m_bContextRetained;
   JBig2ArithCtx* m_gbContext;
   JBig2ArithCtx* m_grContext;
 };
 
-#endif
+#endif  // CORE_SRC_FXCODEC_JBIG2_JBIG2_SYMBOLDICT_H_