Delete old files after an update.

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',
     'branding_dir': 'app/theme/<(branding_path_component)',
     'branding_dir_100': 'app/theme/default_100_percent/<(branding_path_component)',
   },
@@ skipping 93 matching lines @@
             'installer/setup/compat_checks_unittest.cc',
             'installer/setup/setup_constants.cc',
             'installer/util/advanced_firewall_manager_win_unittest.cc',
             'installer/util/beacons_unittest.cc',
             'installer/util/callback_work_item_unittest.cc',
             'installer/util/channel_info_unittest.cc',
             'installer/util/copy_tree_work_item_unittest.cc',
             'installer/util/create_dir_work_item_unittest.cc',
             'installer/util/create_reg_key_work_item_unittest.cc',
             'installer/util/delete_after_reboot_helper_unittest.cc',
+            'installer/util/delete_old_versions_unittest.cc',
             'installer/util/delete_reg_key_work_item_unittest.cc',
             'installer/util/delete_reg_value_work_item_unittest.cc',
             'installer/util/delete_tree_work_item_unittest.cc',
             'installer/util/duplicate_tree_detector_unittest.cc',
             'installer/util/fake_installation_state.h',
             'installer/util/fake_product_state.h',
             'installer/util/google_update_settings_unittest.cc',
             'installer/util/install_util_unittest.cc',
             'installer/util/installation_validation_helper.cc',
             'installer/util/installation_validation_helper.h',
@@ skipping 1003 matching lines @@
             '../build/isolate.gypi',
           ],
           'sources': [
             'setup_unittests.isolate',
           ],
         },
       ],
     }],
   ],
 }