Add type cast definitions for CPDF_Stream.

fpdfsdk/src/fpdf_flatten.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 "../../public/fpdf_flatten.h"
 #include "../include/fsdk_define.h"
 
 typedef CFX_ArrayTemplate<CPDF_Dictionary*> CPDF_ObjectArray;
@@ skipping 193 matching lines @@
     }
     return;
   }
 
   int iType = pContentsObj->GetType();
   CPDF_Array* pContentsArray = NULL;
 
   switch (iType) {
     case PDFOBJ_STREAM: {
       pContentsArray = new CPDF_Array;
-      CPDF_Stream* pContents = (CPDF_Stream*)pContentsObj;
+      CPDF_Stream* pContents = pContentsObj->AsStream();
       FX_DWORD dwObjNum = pDocument->AddIndirectObject(pContents);
       CPDF_StreamAcc acc;
       acc.LoadAllData(pContents);
       CFX_ByteString sStream = "q\n";
       CFX_ByteString sBody =
           CFX_ByteString((const FX_CHAR*)acc.GetData(), acc.GetSize());
       sStream = sStream + sBody + "\nQ";
       pContents->SetData((const uint8_t*)sStream, sStream.GetLength(), FALSE,
                          FALSE);
       pContentsArray->AddReference(pDocument, dwObjNum);
@@ skipping 215 matching lines @@
         pAPStream = pAPDic->GetStream(sAnnotState);
       } else {
         FX_POSITION pos = pAPDic->GetStartPos();
         if (pos) {
           CFX_ByteString sKey;
           CPDF_Object* pFirstObj = pAPDic->GetNextElement(pos, sKey);
           if (pFirstObj) {
             if (pFirstObj->GetType() == PDFOBJ_REFERENCE)
               pFirstObj = pFirstObj->GetDirect();
 
-            if (pFirstObj->GetType() != PDFOBJ_STREAM)
+            if (!pFirstObj->IsStream())
               continue;
 
-            pAPStream = (CPDF_Stream*)pFirstObj;
+            pAPStream = pFirstObj->AsStream();
           }
         }
       }
     }
-
     if (!pAPStream)
       continue;
 
     CPDF_Dictionary* pAPDic = pAPStream->GetDict();
     CFX_AffineMatrix matrix = pAPDic->GetMatrix("Matrix");
 
     CPDF_Rect rcStream;
     if (pAPDic->KeyExist("Rect"))
       rcStream = pAPDic->GetRect("Rect");
     else if (pAPDic->KeyExist("BBox"))
@@ skipping 47 matching lines @@
     pNewXObject->SetData((const uint8_t*)sStream, sStream.GetLength(), FALSE,
                          FALSE);
   }
   pPageDict->RemoveAt("Annots");
 
   ObjectArray.RemoveAll();
   RectArray.RemoveAll();
 
   return FLATTEN_SUCCESS;
 }