Refcount all the IFX_ stream classes all the time.

fpdfsdk/fpdfxfa/cpdfxfa_context.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 "fpdfsdk/fpdfxfa/cpdfxfa_context.h"
 
 #include <utility>
 
@@ skipping 310 matching lines @@
     pBuff[nLength] = 0;
     pBuff[nLength + 1] = 0;
     wsAnswer = CFX_WideString::FromUTF16LE(
         reinterpret_cast<const unsigned short*>(pBuff),
         nLength / sizeof(unsigned short));
   }
   delete[] pBuff;
   return wsAnswer;
 }
 
-IFX_SeekableReadStream* CPDFXFA_Context::DownloadURL(
+CFX_RetainPtr<IFX_SeekableReadStream> CPDFXFA_Context::DownloadURL(
     const CFX_WideString& wsURL) {
   return m_pFormFillEnv ? m_pFormFillEnv->DownloadFromURL(wsURL.c_str())
                         : nullptr;
 }
 
 bool CPDFXFA_Context::PostRequestURL(const CFX_WideString& wsURL,
                                      const CFX_WideString& wsData,
                                      const CFX_WideString& wsContentType,
                                      const CFX_WideString& wsEncode,
                                      const CFX_WideString& wsHeader,
@@ skipping 111 matching lines @@
       return;
   }
 }
 
 IFWL_AdapterTimerMgr* CPDFXFA_Context::GetTimerMgr() {
   CXFA_FWLAdapterTimerMgr* pAdapter = nullptr;
   if (m_pFormFillEnv)
     pAdapter = new CXFA_FWLAdapterTimerMgr(m_pFormFillEnv);
   return pAdapter;
 }