Open NaCl IRT file only once at startup

chrome/common/nacl_messages.h

 // Copyright (c) 2011 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.
 
 // Defines messages between the browser and NaCl process.
 
 // Multiply-included message file, no traditional include guard.
 #include "base/process.h"
 #include "chrome/common/nacl_types.h"
 #include "ipc/ipc_message_macros.h"
 
 #ifndef CHROME_COMMON_NACL_MESSAGES_H_
 #define CHROME_COMMON_NACL_MESSAGES_H_
 
 #endif  // CHROME_COMMON_NACL_MESSAGES_H_
 
 #define IPC_MESSAGE_START NaClMsgStart
 
 //-----------------------------------------------------------------------------
 // NaClProcess messages
 // These are messages sent from the browser to the NaCl process.
 // Tells the NaCl process to start.
-IPC_MESSAGE_CONTROL2(NaClProcessMsg_Start,
-                     std::vector<nacl::FileDescriptor> /* sockets */,
-                     bool /* have_irt_file */)
+IPC_MESSAGE_CONTROL1(NaClProcessMsg_Start,
+                     std::vector<nacl::FileDescriptor> /* sockets */)
 
 // Tells the NaCl broker to launch a NaCl loader process.
 IPC_MESSAGE_CONTROL1(NaClProcessMsg_LaunchLoaderThroughBroker,
                      std::wstring /* channel ID for the loader */)
 
 // Notify the browser process that the loader was launched successfully.
 IPC_MESSAGE_CONTROL2(NaClProcessMsg_LoaderLaunched,
                      std::wstring,  /* channel ID for the loader */
                      base::ProcessHandle /* loader process handle */)
 
 // Notify the broker that all loader processes have been terminated and it
 // should shutdown.
 IPC_MESSAGE_CONTROL0(NaClProcessMsg_StopBroker)
-