When launching PNaCl helper nexes, explicitly disable IRT loading.

ppapi/native_client/src/trusted/plugin/nacl_entry_points.h

 /*
  * Copyright (c) 2012 The Chromium Authors. All rights reserved.
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef NATIVE_CLIENT_SRC_TRUSTED_PLUGIN_NACL_ENTRY_POINTS_H_
 #define NATIVE_CLIENT_SRC_TRUSTED_PLUGIN_NACL_ENTRY_POINTS_H_
 
 #include <stddef.h>
 
 #include <map>
 #include <string>
 
 #include "native_client/src/shared/imc/nacl_imc.h"
 #include "ppapi/c/pp_instance.h"
 #include "ppapi/c/private/ppb_nacl_private.h"
 
 typedef PP_NaClResult (*LaunchNaClProcessFunc)(PP_Instance instance,
                                                const char* alleged_url,
+                                               PP_Bool uses_irt,
                                                PP_Bool uses_ppapi,
                                                PP_Bool enable_ppapi_dev,
                                                nacl::Handle* result_socket);
 
 
 extern LaunchNaClProcessFunc launch_nacl_process;
 
 #endif  // NATIVE_CLIENT_SRC_TRUSTED_PLUGIN_NACL_ENTRY_POINTS_H_