Add type cast definitions for CPDF_Stream.

core/src/fpdfapi/fpdf_edit/fpdf_edit_content.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_serial.h"
 #include "../../../include/fpdfapi/fpdf_module.h"
 #include "../fpdf_page/pageint.h"
@@ skipping 113 matching lines @@
     return;
 
   CFX_ByteTextBuf buf;
   if (CPDF_Array* pArray = pContent->AsArray()) {
     int iCount = pArray->GetCount();
     CPDF_StreamAcc** pContentArray = FX_Alloc(CPDF_StreamAcc*, iCount);
     int size = 0;
     int i = 0;
     for (i = 0; i < iCount; ++i) {
       pContent = pArray->GetElement(i);
-      if (!pContent || pContent->GetType() != PDFOBJ_STREAM) {
+      CPDF_Stream* pStream = ToStream(pContent);
+      if (!pStream)
         continue;
-      }
-      CPDF_StreamAcc* pStream = new CPDF_StreamAcc();
-      pStream->LoadAllData((CPDF_Stream*)pContent);
-      pContentArray[i] = pStream;
+
+      CPDF_StreamAcc* pStreamAcc = new CPDF_StreamAcc();
+      pStreamAcc->LoadAllData(pStream);
+      pContentArray[i] = pStreamAcc;
       size += pContentArray[i]->GetSize() + 1;
     }
     int pos = 0;
     uint8_t* pBuf = FX_Alloc(uint8_t, size);
     for (i = 0; i < iCount; ++i) {
       FXSYS_memcpy(pBuf + pos, pContentArray[i]->GetData(),
                    pContentArray[i]->GetSize());
       pos += pContentArray[i]->GetSize() + 1;
       pBuf[pos - 1] = ' ';
       delete pContentArray[i];
     }
     ProcessForm(buf, pBuf, size, matrix);
     FX_Free(pBuf);
     FX_Free(pContentArray);
-  } else if (pContent->GetType() == PDFOBJ_STREAM) {
+  } else if (CPDF_Stream* pStream = pContent->AsStream()) {
     CPDF_StreamAcc contentStream;
-    contentStream.LoadAllData((CPDF_Stream*)pContent);
+    contentStream.LoadAllData(pStream);
     ProcessForm(buf, contentStream.GetData(), contentStream.GetSize(), matrix);
   }
   CPDF_Stream* pStream = new CPDF_Stream(NULL, 0, NULL);
   pStream->SetData(buf.GetBuffer(), buf.GetLength(), FALSE, FALSE);
   m_pDocument->AddIndirectObject(pStream);
   m_pPage->m_pFormDict->SetAtReference("Contents", m_pDocument,
                                        pStream->GetObjNum());
 }