Improve handling of invalid command line in Me2Me host.

remoting/host/desktop_process_main.cc

 // 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.
 //
 // This file implements the Windows service controlling Me2Me host processes
 // running within user sessions.
 
 #include <utility>
 
 #include "base/bind.h"
@@ skipping 14 matching lines @@
 
 namespace remoting {
 
 int DesktopProcessMain() {
   const base::CommandLine* command_line =
       base::CommandLine::ForCurrentProcess();
   std::string channel_name =
       command_line->GetSwitchValueASCII(kDaemonPipeSwitchName);
 
   if (channel_name.empty())
-    return kUsageExitCode;
+    return kInvalidCommandLineExitCode;
 
   base::MessageLoopForUI message_loop;
   base::RunLoop run_loop;
   scoped_refptr<AutoThreadTaskRunner> ui_task_runner =
       new AutoThreadTaskRunner(message_loop.task_runner(),
                                run_loop.QuitClosure());
 
   // Launch the video capture thread.
   scoped_refptr<AutoThreadTaskRunner> video_capture_task_runner =
       AutoThread::Create("Video capture thread", ui_task_runner);
@@ skipping 30 matching lines @@
   return kSuccessExitCode;
 }
 
 }  // namespace remoting
 
 #if !defined(OS_WIN)
 int main(int argc, char** argv) {
   return remoting::HostMain(argc, argv);
 }
 #endif  // !defined(OS_WIN)