Add type cast definitions for CPDF_Stream.

core/src/fpdfapi/fpdf_page/fpdf_page_doc.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/fpdfapi/fpdf_page.h"
 #include "../../../include/fpdfapi/fpdf_module.h"
 #include "../../../include/fdrm/fx_crypt.h"
 #include "../fpdf_font/font_int.h"
@@ skipping 452 matching lines @@
   if (!pImageStream)
     return nullptr;
 
   const FX_DWORD dwImageObjNum = pImageStream->GetObjNum();
   auto it = m_ImageMap.find(dwImageObjNum);
   if (it != m_ImageMap.end()) {
     return it->second->AddRef();
   }
 
   CPDF_Image* pImage = new CPDF_Image(m_pPDFDoc);
-  pImage->LoadImageF((CPDF_Stream*)pImageStream, FALSE);
+  pImage->LoadImageF(pImageStream->AsStream(), FALSE);
 
   CPDF_CountedImage* imageData = new CPDF_CountedImage(pImage);
   m_ImageMap[dwImageObjNum] = imageData;
   return imageData->AddRef();
 }
 
 void CPDF_DocPageData::ReleaseImage(CPDF_Object* pImageStream) {
   if (!pImageStream || !pImageStream->GetObjNum())
     return;
 
@@ skipping 112 matching lines @@
 }
 
 CPDF_CountedPattern* CPDF_DocPageData::FindPatternPtr(
     CPDF_Object* pPatternObj) const {
   if (!pPatternObj)
     return nullptr;
 
   auto it = m_PatternMap.find(pPatternObj);
   return it != m_PatternMap.end() ? it->second : nullptr;
 }