Refcount IFGAS_ streams all the time, too

testing/libfuzzer/pdf_css_fuzzer.cc

Index: testing/libfuzzer/pdf_css_fuzzer.cc
diff --git a/testing/libfuzzer/pdf_css_fuzzer.cc b/testing/libfuzzer/pdf_css_fuzzer.cc
index 96877f40be309d76571bd94d135f23ec2153d062..247c9b92453b38790182ef6d80b76839a5f4ffe1 100644
--- a/testing/libfuzzer/pdf_css_fuzzer.cc
+++ b/testing/libfuzzer/pdf_css_fuzzer.cc
@@ -4,6 +4,7 @@
 
 #include <memory>
 
+#include "core/fxcrt/cfx_retain_ptr.h"
 #include "core/fxcrt/fx_string.h"
 #include "xfa/fde/css/fde_css.h"
 #include "xfa/fde/css/fde_csssyntax.h"
@@ -11,16 +12,15 @@
 #include "xfa/fxfa/parser/cxfa_widetextread.h"
 
 extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
-  CFDE_CSSSyntaxParser parser;
-
   CFX_WideString input = CFX_WideString::FromUTF8(
       CFX_ByteStringC(data, static_cast<FX_STRSIZE>(size)));
-  std::unique_ptr<IFGAS_Stream, ReleaseDeleter<IFGAS_Stream>> stream(
-      new CXFA_WideTextRead(input));
+
+  auto stream = pdfium::MakeRetain<CXFA_WideTextRead>(input);
   if (!stream)
     return 0;
 
-  parser.Init(stream.get(), 1024);
+  CFDE_CSSSyntaxParser parser;
+  parser.Init(stream, 1024);
 
   FDE_CSSSYNTAXSTATUS status = parser.DoSyntaxParse();
   while (status != FDE_CSSSYNTAXSTATUS_Error &&