Add type cast definitions for CPDF_Stream.

fpdfsdk/src/fsdk_baseform.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 "../../third_party/base/nonstd_unique_ptr.h"
 #include "../include/fsdk_define.h"
 #include "../include/fsdk_mgr.h"
 #include "../include/fsdk_baseannot.h"
@@ skipping 44 matching lines @@
   if (!psub)
     return FALSE;
 
   int nFieldType = GetFieldType();
   switch (nFieldType) {
     case FIELDTYPE_PUSHBUTTON:
     case FIELDTYPE_COMBOBOX:
     case FIELDTYPE_LISTBOX:
     case FIELDTYPE_TEXTFIELD:
     case FIELDTYPE_SIGNATURE:
-      return psub->GetType() == PDFOBJ_STREAM;
+      return psub->IsStream();
     case FIELDTYPE_CHECKBOX:
     case FIELDTYPE_RADIOBUTTON:
       if (CPDF_Dictionary* pSubDict = psub->AsDictionary()) {
         return pSubDict->GetStream(GetAppState()) != NULL;
       }
       return FALSE;
   }
   return TRUE;
 }
 
@@ skipping 2531 matching lines @@
   ASSERT(pAnnot != NULL);
 
   CPDF_Annot* pPDFAnnot = pAnnot->GetPDFAnnot();
   ASSERT(pPDFAnnot != NULL);
 
   CPDF_Rect rcAnnot;
   pPDFAnnot->GetRect(rcAnnot);
 
   return rcAnnot;
 }