Fix extension packer command-line code for Mac

chrome/common/result_codes.h

 // Copyright (c) 2010 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 CHROME_COMMON_RESULT_CODES_H_
 #define CHROME_COMMON_RESULT_CODES_H_
 #pragma once
 
 #include "base/process_util.h"
 
@@ skipping 40 matching lines @@
                                 // depends on the experiment.
 
     NORMAL_EXIT_CANCEL,         // For experiments this return code means that
                                 // the user canceled causes the did_run "dr"
                                 // signal to be reset so this chrome run does
                                 // not count as active chrome usage.
 
     PROFILE_IN_USE,             // The profile was in use on another host.
 
     UNINSTALL_EXTENSION_ERROR,  // Failed to silently uninstall an extension.
+    PACK_EXTENSION_ERROR,       // Failed to pack an extension via the cmd line.
 
     EXIT_LAST_CODE              // Last return code (keep it last).
   };
 };
 
 #endif  // CHROME_COMMON_RESULT_CODES_H_