Fix a leak in CJBig2_CachePair.

core/src/fxcodec/codec/fx_codec_jbig.cpp

 // 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
 
 #include "../../../include/fxcodec/fx_codec.h"
 #include "codec_int.h"
 
 CCodec_Jbig2Context::CCodec_Jbig2Context() {
   FXSYS_memset(this, 0, sizeof(CCodec_Jbig2Context));
 }
-CCodec_Jbig2Module::~CCodec_Jbig2Module() {}
+
+CCodec_Jbig2Module::~CCodec_Jbig2Module() {
+  for (auto it : m_SymbolDictCache) {
+    delete it.second;
+  }
+}
+
 void* CCodec_Jbig2Module::CreateJbig2Context() {
   return new CCodec_Jbig2Context();
 }
 void CCodec_Jbig2Module::DestroyJbig2Context(void* pJbig2Content) {
   if (pJbig2Content) {
     CJBig2_Context::DestroyContext(
         ((CCodec_Jbig2Context*)pJbig2Content)->m_pContext);
     delete (CCodec_Jbig2Context*)pJbig2Content;
   }
   pJbig2Content = NULL;
@@ skipping 73 matching lines @@
     return FXCODEC_STATUS_ERROR;
   }
   int dword_size =
       m_pJbig2Context->m_height * m_pJbig2Context->m_dest_pitch / 4;
   FX_DWORD* dword_buf = (FX_DWORD*)m_pJbig2Context->m_dest_buf;
   for (int i = 0; i < dword_size; i++) {
     dword_buf[i] = ~dword_buf[i];
   }
   return FXCODEC_STATUS_DECODE_FINISH;
 }