Put CJBig2_SymbolDict's images in a CJBig2_List container.

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 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_List.h"
 
 class CJBig2_Image;
+struct JBig2ArithCtx;
 
 class CJBig2_SymbolDict {
  public:
   CJBig2_SymbolDict();
   ~CJBig2_SymbolDict();
 
   nonstd::unique_ptr<CJBig2_SymbolDict> DeepCopy() const;
 
+  // Takes ownership of |image|.
+  void AddImage(CJBig2_Image* image) { m_SDEXSYMS.push_back(image); }
+
+  size_t NumImages() const { return m_SDEXSYMS.size(); }
+  CJBig2_Image* GetImage(size_t index) const { return m_SDEXSYMS.get(index); }
+
  public:
-  FX_DWORD SDNUMEXSYMS;
-  CJBig2_Image** SDEXSYMS;
   FX_BOOL m_bContextRetained;
   JBig2ArithCtx* m_gbContext;
   JBig2ArithCtx* m_grContext;
+
+ private:
+  CJBig2_List<CJBig2_Image> m_SDEXSYMS;
 };
 
 #endif  // CORE_SRC_FXCODEC_JBIG2_JBIG2_SYMBOLDICT_H_