[Chromoting] Refactored worker process launching code and speeded up the desktop process launch.

remoting/host/host_main.cc

 // Copyright (c) 2013 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 common entry point shared by all Chromoting Host
 // processes.
 
 #include "remoting/host/host_main.h"
 
 #include <string>
@@ skipping 107 matching lines @@
   // Launch the child process requesting elevation.
   SHELLEXECUTEINFO info;
   memset(&info, 0, sizeof(info));
   info.cbSize = sizeof(info);
   info.lpVerb = L"runas";
   info.lpFile = binary.value().c_str();
   info.lpParameters = parameters.c_str();
   info.nShow = SW_SHOWNORMAL;
 
   if (!ShellExecuteEx(&info)) {
-    return GetLastError();
+    DWORD exit_code = GetLastError();
+    LOG_GETLASTERROR(ERROR) << "Unable to launch '" << binary.value() << "'";
+    return exit_code;
   }
 
   return kSuccessExitCode;
 }
 
 #endif  // defined(OS_WIN)
 
 // Select the entry point corresponding to the process type.
 MainRoutineFn SelectMainRoutine(const std::string& process_type) {
   MainRoutineFn main_routine = NULL;
@@ skipping 90 matching lines @@
 
   // Invoke the entry point.
   int exit_code = main_routine();
   if (exit_code == kUsageExitCode) {
     Usage(command_line->GetProgram());
   }
   return exit_code;
 }
 
 }  // namespace remoting