Sanitize CJBig2_SymbolDict's memory usage.

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 <vector>
+
 #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_BOOL m_bContextRetained;
-  JBig2ArithCtx* m_gbContext;
-  JBig2ArithCtx* m_grContext;
+  const std::vector<JBig2ArithCtx>& GbContext() const { return m_gbContext; }
+  const std::vector<JBig2ArithCtx>& GrContext() const { return m_grContext; }
+
+  void SetGbContext(const std::vector<JBig2ArithCtx>& gbContext) {
+    m_gbContext = gbContext;

[Tom Sepez, 2015/10/09 16:10:52]

maybe std::vector<>&&  and use nonstd::move when calling this to avoid copying
the elts?

[Lei Zhang, 2015/10/09 18:59:52]

+thakis - I thought we don't do that yet?

[Nico, 2015/10/09 20:23:24]

chromium-cpp.appspot.com hopefully applies to pdfium too. rvalue refs aren't
generally allowed
(https://groups.google.com/a/chromium.org/forum/#!msg/chromium-dev/xMscQuYBwyc...
"(for example, if you want to   allow rvalue references, you should be able to
make a convincing case that most chromium developers can explain the difference
between std::move and std::forward)"… even with pdfium's much smaller crew, I'm
not sure if that applies with s/chromium/pdfium/)

+  }
+  void SetGrContext(const std::vector<JBig2ArithCtx>& grContext) {
+    m_grContext = grContext;
+  }
 
  private:
+  std::vector<JBig2ArithCtx> m_gbContext;
+  std::vector<JBig2ArithCtx> m_grContext;
   CJBig2_List<CJBig2_Image> m_SDEXSYMS;
 };
 
 #endif  // CORE_SRC_FXCODEC_JBIG2_JBIG2_SYMBOLDICT_H_