Fix reporting or errors addin building and testing

visual_studio/NativeClientVSAddIn/InstallerResources/install.py

 #!/usr/bin/env python
 # 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.
 
 """Copies necessary add-in files into place to install the add-in.
 
 This script will copy the necessary files for the Visual Studio add-in
 to where Visual Studio can find them. It assumes the current directory
 contains the necessary files to copy.
@@ skipping 197 matching lines @@
     if options.install_ppapi:
       create_ppapi_platform.CreatePPAPI(options.msbuild_path)
       print "PPAPI platform installed."
   except:
     print "\nException occured! Rolling back install...\n"
     Uninstall(nacl_directory, pepper_directory, addin_directory)
     raise
   else:
     print "\nInstallation complete!\n"
 
+  return 0
+
 if __name__ == '__main__':
+  rtn = 1
   try:
-    main()
+    rtn = main()
   except InstallError as e:
     print
     print e
   except shutil.Error as e:
     print "Error while copying file. Please ensure file is not in use."
     print e
   except WindowsError as e:
     if e.winerror == 5:
       print "Access denied error.  Please ensure Visual Studio and MSBuild"
       print "processes are closed."
     else:
       raise
+  sys.exit(rtn)