Make a bunch of JBig2 classes independent of CJBig2_Object.

core/src/fxcodec/jbig2/JBig2_HuffmanDecoder.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_HUFFMAN_DECODER_H_
 #define _JBIG2_HUFFMAN_DECODER_H_
 #include "JBig2_BitStream.h"
 #include "JBig2_HuffmanTable.h"
-class CJBig2_HuffmanDecoder : public CJBig2_Object {
+class CJBig2_HuffmanDecoder {
  public:
   CJBig2_HuffmanDecoder(CJBig2_BitStream* pStream);
 
   ~CJBig2_HuffmanDecoder();
 
   int decodeAValue(CJBig2_HuffmanTable* pTable, int* nResult);
 
  private:
   CJBig2_BitStream* m_pStream;
 };
 #endif