Remove "this==NULL" and adjust corresponding callers

core/include/fpdfapi/fpdf_resource.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 _FPDF_RESOURCE_
 #define _FPDF_RESOURCE_
 #ifndef _FPDF_PARSER_
 #include "fpdf_parser.h"
@@ skipping 864 matching lines @@
         return m_pInlineDict;
     }
 
     CPDF_Stream*                        GetStream() const
     {
         return m_pStream;
     }
 
     CPDF_Dictionary*            GetDict() const
     {
-        return m_pStream->GetDict();
+        return m_pStream? m_pStream->GetDict(): NULL;
     }
 
     CPDF_Dictionary*            GetOC() const
     {
         return m_pOC;
     }
 
     CPDF_Document*                      GetDocument() const
     {
         return m_pDocument;
@@ skipping 55 matching lines @@
     FX_BOOL                                     m_bIsMask;
 
     FX_BOOL                                     m_bInterpolate;
 
     CPDF_Document*                      m_pDocument;
 
     CPDF_Dictionary*            m_pOC;
     CPDF_Dictionary*    InitJPEG(FX_LPBYTE pData, FX_DWORD size);
 };
 #endif