Make CPDF_Image() constructors saner.

core/fpdfapi/parser/cpdf_stream.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_FPDFAPI_PARSER_CPDF_STREAM_H_
 #define CORE_FPDFAPI_PARSER_CPDF_STREAM_H_
 
 #include <memory>
@@ skipping 40 matching lines @@
       bool bDirect,
       std::set<const CPDF_Object*>* pVisited) const override;
 
   std::unique_ptr<CPDF_Dictionary, ReleaseDeleter<CPDF_Dictionary>> m_pDict;
   bool m_bMemoryBased = true;
   uint32_t m_dwSize = 0;
   std::unique_ptr<uint8_t, FxFreeDeleter> m_pDataBuf;
   IFX_FileRead* m_pFile = nullptr;
 };
 
-using UniqueStream = std::unique_ptr<CPDF_Stream, ReleaseDeleter<CPDF_Stream>>;
+using UniqueStream = std::unique_ptr<CPDF_Stream, ReleaseDeleter<CPDF_Object>>;
 
 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;
 }
 
+inline UniqueStream ToStream(UniqueObject obj) {
+  CPDF_Stream* pStream = ToStream(obj.get());
+  if (!pStream)
+    return nullptr;
+  obj.release();
+  return UniqueStream(pStream);
+}
+
 #endif  // CORE_FPDFAPI_PARSER_CPDF_STREAM_H_