Add chrome, installer_util targets to GN build.

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' is set in the 'conditions' section at the bottom.
   },
@@ skipping 132 matching lines @@
             'VCManifestTool': {
               'AdditionalManifestFiles': [
                 '$(ProjectDir)\\installer\\mini_installer\\mini_installer.exe.manifest',
               ],
             },
           },
           # TODO(jschuh): crbug.com/167187 fix size_t to int truncations.
           'msvs_disabled_warnings': [ 4267, ],
         },
         {
+          # GN version: //chrome/installer/util:strings
           'target_name': 'installer_util_strings',
           'type': 'none',
           'actions': [
             {
               'action_name': 'installer_util_strings',
               'variables': {
                 'create_string_rc_py': 'installer/util/prebuild/create_string_rc.py',
               },
               'conditions': [
                 ['branding=="Chrome"', {
@@ skipping 925 matching lines @@
          'branding_dir_100': 'app/theme/default_100_percent/google_chrome',
       },
     }, { # else branding!="Chrome"
       'variables': {
          'branding_dir': 'app/theme/chromium',
          'branding_dir_100': 'app/theme/default_100_percent/chromium',
       },
     }],
   ],
 }