Add fuzzer for CPDF_StreamParser

testing/libfuzzer/pdf_streamparser_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 "core/fpdfapi/fpdf_page/cpdf_psengine.h"
+#include "core/fpdfapi/fpdf_page/pageint.h"
 
 #include <cstdint>
 
+#include "core/fpdfapi/fpdf_parser/include/cpdf_object.h"
+
 extern "C" int LLVMFuzzerTestOneInput(const uint8_t* data, size_t size) {
-  CPDF_PSEngine engine;
-  if (engine.Parse(reinterpret_cast<const char*>(data), size))
-    engine.Execute();
+  CPDF_StreamParser parser(data, size);
+  while (CPDF_Object* pObj = parser.ReadNextObject(true, 0))
+    pObj->Release();
+
   return 0;
 }