Refcount all the IFX_ stream classes all the time.

xfa/fxfa/app/xfa_checksum.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 "xfa/fxfa/xfa_checksum.h"
 
 #include "core/fdrm/crypto/fx_crypt.h"
 
@@ skipping 207 matching lines @@
 }
 
 void CXFA_ChecksumContext::StartChecksum() {
   FinishChecksum();
   m_pByteContext = FX_Alloc(uint8_t, 128);
   CRYPT_SHA1Start(m_pByteContext);
   m_bsChecksum.clear();
   m_pSAXReader = new CFX_SAXReader;
 }
 
-bool CXFA_ChecksumContext::UpdateChecksum(IFX_SeekableReadStream* pSrcFile,
-                                          FX_FILESIZE offset,
-                                          size_t size) {
+bool CXFA_ChecksumContext::UpdateChecksum(
+    const CFX_RetainPtr<IFX_SeekableReadStream>& pSrcFile,
+    FX_FILESIZE offset,
+    size_t size) {
   if (!m_pSAXReader || !pSrcFile)
     return false;
+
   if (size < 1)
     size = pSrcFile->GetSize();
 
   CXFA_SAXReaderHandler handler(this);
   m_pSAXReader->SetHandler(&handler);
   if (m_pSAXReader->StartParse(
           pSrcFile, (uint32_t)offset, (uint32_t)size,
           CFX_SaxParseMode_NotSkipSpace | CFX_SaxParseMode_NotConvert_amp |
               CFX_SaxParseMode_NotConvert_lt | CFX_SaxParseMode_NotConvert_gt |
               CFX_SaxParseMode_NotConvert_sharp) < 0) {
@@ skipping 20 matching lines @@
 
 CFX_ByteString CXFA_ChecksumContext::GetChecksum() const {
   return m_bsChecksum;
 }
 
 void CXFA_ChecksumContext::Update(const CFX_ByteStringC& bsText) {
   if (m_pByteContext) {
     CRYPT_SHA1Update(m_pByteContext, bsText.raw_str(), bsText.GetLength());
   }
 }