Introduce UserHiveVisitor for performing operations on local users' registry hives.

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.
 
 {
   'includes': [
     '../media/cdm_paths.gypi',
   ],
   'variables': {
     'lastchange_path': '../build/util/LASTCHANGE',
@@ skipping 276 matching lines @@
             'installer/setup/installer_crash_reporting.cc',
             'installer/setup/installer_crash_reporting.h',
             'installer/setup/installer_metrics.cc',
             'installer/setup/installer_metrics.h',
             'installer/setup/setup_constants.cc',
             'installer/setup/setup_constants.h',
             'installer/setup/setup_util.cc',
             'installer/setup/setup_util.h',
             'installer/setup/update_active_setup_version_work_item.cc',
             'installer/setup/update_active_setup_version_work_item.h',
+            'installer/setup/user_hive_visitor.cc',
+            'installer/setup/user_hive_visitor.h',
           ],
         },
         {
           # GN version: //chrome/installer/setup
           'target_name': 'setup',
           'type': 'executable',
           'dependencies': [
             'setup_lib',
             '../chrome/chrome.gyp:install_static_util',
             '../chrome/common_constants.gyp:common_constants',
@@ skipping 106 matching lines @@
             'installer/mini_installer/regkey.cc',
             'installer/mini_installer/regkey.h',
             'installer/setup/archive_patch_helper_unittest.cc',
             'installer/setup/install_unittest.cc',
             'installer/setup/install_worker_unittest.cc',
             'installer/setup/memory_unittest.cc',
             'installer/setup/run_all_unittests.cc',
             'installer/setup/setup_util_unittest.cc',
             'installer/setup/setup_util_unittest.h',
             'installer/setup/update_active_setup_version_work_item_unittest.cc',
+            'installer/setup/user_hive_visitor_unittest.cc',
           ],
           # TODO(jschuh): crbug.com/167187 fix size_t to int truncations.
           'msvs_disabled_warnings': [ 4267, ],
         },
       ],
     }],
     ['OS=="win" and target_arch=="ia32"', {
       'targets': [
         {
           'target_name': 'launcher_support64',
@@ skipping 743 matching lines @@
             '../build/isolate.gypi',
           ],
           'sources': [
             'setup_unittests.isolate',
           ],
         },
       ],
     }],
   ],
 }