Split CPDF_Stream/CPDF_StreamAcc into separate files

core/include/fpdfapi/cpdf_object.h

 // Copyright 2016 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
 
 #ifndef CORE_INCLUDE_FPDFAPI_CPDF_OBJECT_H_
 #define CORE_INCLUDE_FPDFAPI_CPDF_OBJECT_H_
 
 #include "core/include/fxcrt/fx_string.h"
@@ skipping 132 matching lines @@
   return obj ? obj->AsDictionary() : nullptr;
 }
 inline CPDF_Reference* ToReference(CPDF_Object* obj) {
   return obj ? obj->AsReference() : nullptr;
 }
 
 inline const CPDF_Reference* ToReference(const CPDF_Object* obj) {
   return obj ? obj->AsReference() : nullptr;
 }
 
+inline CPDF_Stream* ToStream(CPDF_Object* obj) {
+  return obj ? obj->AsStream() : nullptr;
+}
+
+inline const CPDF_Stream* ToStream(const CPDF_Object* obj) {
+  return obj ? obj->AsStream() : nullptr;
+}
+
 #endif  // CORE_INCLUDE_FPDFAPI_CPDF_OBJECT_H_