Various changes to JBig2 cache:

core/src/fxcodec/jbig2/JBig2_BitStream.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_BITSTREAM_H_
 #define CORE_SRC_FXCODEC_JBIG2_JBIG2_BITSTREAM_H_
 
 #include "../../../include/fxcrt/fx_basic.h"
 
+class CPDF_StreamAcc;
+
 class CJBig2_BitStream {
  public:
-  CJBig2_BitStream(const uint8_t* pBuffer, FX_DWORD dwLength);
+  explicit CJBig2_BitStream(CPDF_StreamAcc* pSrcStream);
   ~CJBig2_BitStream();
 
   // TODO(thestig): readFoo() should return bool.
   int32_t readNBits(FX_DWORD nBits, FX_DWORD* dwResult);
   int32_t readNBits(FX_DWORD nBits, int32_t* nResult);
   int32_t read1Bit(FX_DWORD* dwResult);
   int32_t read1Bit(FX_BOOL* bResult);
   int32_t read1Byte(uint8_t* cResult);
   int32_t readInteger(FX_DWORD* dwResult);
   int32_t readShortInteger(FX_WORD* wResult);
   void alignByte();
   uint8_t getCurByte() const;
   void incByteIdx();
   uint8_t getCurByte_arith() const;
   uint8_t getNextByte_arith() const;
   FX_DWORD getOffset() const;
   void setOffset(FX_DWORD dwOffset);
   FX_DWORD getBitPos() const;
   void setBitPos(FX_DWORD dwBitPos);
   const uint8_t* getBuf() const;
   FX_DWORD getLength() const { return m_dwLength; }
   const uint8_t* getPointer() const;
   void offset(FX_DWORD dwOffset);
   FX_DWORD getByteLeft() const;
+  FX_DWORD getObjNum() const;
 
  private:
   void AdvanceBit();
   bool IsInBound() const;
   FX_DWORD LengthInBits() const;
 
   const uint8_t* m_pBuf;
   FX_DWORD m_dwLength;
   FX_DWORD m_dwByteIdx;
   FX_DWORD m_dwBitIdx;
+  const FX_DWORD m_dwObjNum;
 
   CJBig2_BitStream(const CJBig2_BitStream&) = delete;
   void operator=(const CJBig2_BitStream&) = delete;
 };
 
 #endif  // CORE_SRC_FXCODEC_JBIG2_JBIG2_BITSTREAM_H_