Refcount all the IFX_ stream classes all the time.

fpdfsdk/cpdfsdk_formfillenvironment.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 FPDFSDK_CPDFSDK_FORMFILLENVIRONMENT_H_
 #define FPDFSDK_CPDFSDK_FORMFILLENVIRONMENT_H_
 
 #include <map>
@@ skipping 131 matching lines @@
                FPDF_WIDESTRING pSubject,
                FPDF_WIDESTRING pCC,
                FPDF_WIDESTRING pBcc,
                FPDF_WIDESTRING pMsg);
   void UploadTo(FPDF_FILEHANDLER* fileHandler,
                 int fileFlag,
                 FPDF_WIDESTRING uploadTo);
   FPDF_FILEHANDLER* OpenFile(int fileType,
                              FPDF_WIDESTRING wsURL,
                              const char* mode);
-  IFX_SeekableReadStream* DownloadFromURL(const FX_WCHAR* url);
+  CFX_RetainPtr<IFX_SeekableReadStream> DownloadFromURL(const FX_WCHAR* url);
   CFX_WideString PostRequestURL(const FX_WCHAR* wsURL,
                                 const FX_WCHAR* wsData,
                                 const FX_WCHAR* wsContentType,
                                 const FX_WCHAR* wsEncode,
                                 const FX_WCHAR* wsHeader);
   FPDF_BOOL PutRequestURL(const FX_WCHAR* wsURL,
                           const FX_WCHAR* wsData,
                           const FX_WCHAR* wsEncode);
   CFX_WideString GetLanguage();
 
@@ skipping 56 matching lines @@
   std::unique_ptr<CPDFSDK_InterForm> m_pInterForm;
   CPDFSDK_Annot::ObservedPtr m_pFocusAnnot;
   UnderlyingDocumentType* m_pUnderlyingDoc;
   std::unique_ptr<CFFL_InteractiveFormFiller> m_pFormFiller;
   std::unique_ptr<CFX_SystemHandler> m_pSysHandler;
   bool m_bChangeMask;
   bool m_bBeingDestroyed;
 };
 
 #endif  // FPDFSDK_CPDFSDK_FORMFILLENVIRONMENT_H_