Refcount IFGAS_ streams all the time, too

testing/libfuzzer/pdf_xml_fuzzer.cc

 // Copyright 2016 The 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.
 
 #include <cstddef>
 #include <cstdint>
 #include <memory>
 
 #include "core/fxcrt/fx_basic.h"
 #include "core/fxcrt/fx_safe_types.h"
@@ skipping 34 matching lines @@
 
 }  // namespace
 
 extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
   FX_SAFE_STRSIZE safe_size = size;
   if (!safe_size.IsValid())
     return 0;
 
   CFX_WideString input =
       CFX_WideString::FromUTF8(CFX_ByteStringC(data, safe_size.ValueOrDie()));
-  std::unique_ptr<IFGAS_Stream, ReleaseDeleter<IFGAS_Stream>> stream(
-      new CXFA_WideTextRead(input));
+  auto stream = pdfium::MakeRetain<CXFA_WideTextRead>(input);
   if (!stream)
     return 0;
 
   std::unique_ptr<CFDE_XMLDoc> doc = pdfium::MakeUnique<CFDE_XMLDoc>();
   std::unique_ptr<CFDE_XMLParser, ReleaseDeleter<CFDE_XMLParser>> parser(
-      new CXFA_XMLParser(doc->GetRoot(), stream.get()));
-
+      new CXFA_XMLParser(doc->GetRoot(), stream));
   if (!doc->LoadXML(parser.release()))
     return 0;
 
   int32_t load_result = doc->DoLoad(nullptr);
   if (load_result < 100)
     return 0;
 
   (void)XFA_FDEExtension_GetDocumentNode(doc.get());
   return 0;
 }