Avoid calling GetNamedPipeClientProcessId() which is not available on XP.

remoting/host/win/worker_process_launcher.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 REMOTING_HOST_WIN_WORKER_PROCESS_LAUNCHER_H_
 #define REMOTING_HOST_WIN_WORKER_PROCESS_LAUNCHER_H_
 
 #include <windows.h>
 
 #include "base/basictypes.h"
@@ skipping 35 matching lines @@
     // Starts the worker process and passes |channel_name| to it.
     // |process_exit_event_out| receives a handle that becomes signalled once
     // the launched process has been terminated.
     virtual bool DoLaunchProcess(
         const std::string& channel_name,
         base::win::ScopedHandle* process_exit_event_out) = 0;
 
     // Terminates the worker process with the given exit code.
     virtual void DoKillProcess(DWORD exit_code) = 0;
 
-    // Notifies that a client has been connected to the channel. |peer_pid|
-    // is the peer process's ID that the delegate can use to verify identity of
-    // the client. The verification code has to make sure that the client
-    // process's PID will not be assigned to another process (for instance by
-    // keeping an opened handle of the client process).
-    virtual void OnChannelConnected(DWORD peer_pid) = 0;
+    // Notifies that a client has been connected to the channel.
+    virtual void OnChannelConnected() = 0;
 
     // Processes messages sent by the client.
     virtual bool OnMessageReceived(const IPC::Message& message) = 0;
   };
 
   // Creates the launcher.
   // |delegate| will be able to receive messages sent over the channel once
   // the worker has been started and until it is stopped by Stop() or an error
   // occurs.
   //
@@ skipping 56 matching lines @@
 
   // The server end of the pipe.
   base::win::ScopedHandle pipe_;
 
   DISALLOW_COPY_AND_ASSIGN(WorkerProcessLauncher);
 };
 
 }  // namespace remoting
 
 #endif  // REMOTING_HOST_WIN_WORKER_PROCESS_LAUNCHER_H_