Make use of the new UpdateActiveSetupVersionWorkItem.

chrome/chrome_installer.gypi

 # 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.
 
 {
   'variables': {
     'lastchange_path': '../build/util/LASTCHANGE',
     'libpeer_target_type%': 'static_library',
     'branding_dir': 'app/theme/<(branding_path_component)',
     'branding_dir_100': 'app/theme/default_100_percent/<(branding_path_component)',
@@ skipping 235 matching lines @@
             'installer/setup/setup_constants.cc',
             'installer/setup/setup_constants.h',
             'installer/setup/setup_exe_version.rc.version',
             'installer/setup/setup_main.cc',
             'installer/setup/setup_main.h',
             'installer/setup/setup_resource.h',
             'installer/setup/setup_util.cc',
             'installer/setup/setup_util.h',
             'installer/setup/uninstall.cc',
             'installer/setup/uninstall.h',
+            'installer/setup/update_active_setup_version_work_item.cc',
+            'installer/setup/update_active_setup_version_work_item.h',
           ],
           'msvs_settings': {
             'VCLinkerTool': {
               'SubSystem': '2',     # Set /SUBSYSTEM:WINDOWS
             },
             'VCManifestTool': {
               'AdditionalManifestFiles': [
                 '$(ProjectDir)\\installer\\setup\\setup.exe.manifest',
               ],
             },
@@ skipping 817 matching lines @@
             '../build/isolate.gypi',
           ],
           'sources': [
             'installer_util_unittests.isolate',
           ],
         },
       ],
     }],
   ],
 }