Refcount all the IFX_ stream classes all the time.

fpdfsdk/fpdfxfa/cpdfxfa_docenvironment.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_FPDFXFA_CPDFXFA_DOCENVIRONMENT_H_
 #define FPDFSDK_FPDFXFA_CPDFXFA_DOCENVIRONMENT_H_
 
+#include "core/fxcrt/cfx_retain_ptr.h"
 #include "public/fpdfview.h"
 #include "xfa/fxfa/fxfa.h"
 
 class CPDFXFA_Context;
 class IJS_Context;
 
 class CPDFXFA_DocEnvironment : public IXFA_DocEnvironment {
  public:
   explicit CPDFXFA_DocEnvironment(CPDFXFA_Context*);
   ~CPDFXFA_DocEnvironment() override;
@@ skipping 58 matching lines @@
    */
   bool SubmitData(CXFA_FFDoc* hDoc, CXFA_Submit submit) override;
 
   bool GetGlobalProperty(CXFA_FFDoc* hDoc,
                          const CFX_ByteStringC& szPropName,
                          CFXJSE_Value* pValue) override;
   bool SetGlobalProperty(CXFA_FFDoc* hDoc,
                          const CFX_ByteStringC& szPropName,
                          CFXJSE_Value* pValue) override;
 
-  IFX_SeekableReadStream* OpenLinkedFile(CXFA_FFDoc* hDoc,
-                                         const CFX_WideString& wsLink) override;
+  CFX_RetainPtr<IFX_SeekableReadStream> OpenLinkedFile(
+      CXFA_FFDoc* hDoc,
+      const CFX_WideString& wsLink) override;
 
  private:
   bool OnBeforeNotifySubmit();
   void OnAfterNotifySubmit();
   bool NotifySubmit(bool bPrevOrPost);
   bool SubmitDataInternal(CXFA_FFDoc* hDoc, CXFA_Submit submit);
   bool MailToInfo(CFX_WideString& csURL,
                   CFX_WideString& csToAddress,
                   CFX_WideString& csCCAddress,
                   CFX_WideString& csBCCAddress,
                   CFX_WideString& csSubject,
                   CFX_WideString& csMsg);
   bool ExportSubmitFile(FPDF_FILEHANDLER* ppFileHandler,
                         int fileType,
                         FPDF_DWORD encodeType,
                         FPDF_DWORD flag);
   void ToXFAContentFlags(CFX_WideString csSrcContent, FPDF_DWORD& flag);
 
   CPDFXFA_Context* const m_pContext;  // Not owned;
   IJS_Context* m_pJSContext;
 };
 
 #endif  // FPDFSDK_FPDFXFA_CPDFXFA_DOCENVIRONMENT_H_