Add type cast definitions for CPDF_Array.

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 208 matching lines @@
       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);
       break;
     }
 
     case PDFOBJ_ARRAY: {
-      pContentsArray = (CPDF_Array*)pContentsObj;
+      pContentsArray = pContentsObj->AsArray();
       break;
     }
     default:
       break;
   }
 
   if (!pContentsArray)
     return;
 
   FX_DWORD dwObjNum = pDocument->AddIndirectObject(pContentsArray);
@@ skipping 276 matching lines @@
     pNewXObject->SetData((const uint8_t*)sStream, sStream.GetLength(), FALSE,
                          FALSE);
   }
   pPageDict->RemoveAt("Annots");
 
   ObjectArray.RemoveAll();
   RectArray.RemoveAll();
 
   return FLATTEN_SUCCESS;
 }