Componentize internal class FlagsState in flags_ui component.

components/flags_ui.gypi

 # Copyright 2015 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.
 
 {
   'targets': [
     {
       # GN version: //components/flags_ui
       'target_name': 'flags_ui',
       'type': 'static_library',
       'include_dirs': [
         '..',
       ],
       'dependencies': [
         '../base/base.gyp:base',
         '../base/base.gyp:base_prefs',
         '../components/components_strings.gyp:components_strings',
         '../ui/base/ui_base.gyp:ui_base',
+        'flags_ui_switches',
       ],
       'sources': [
         # Note: sources list duplicated in GN build.
         'flags_ui/feature_entry.cc',
         'flags_ui/feature_entry.h',
         'flags_ui/feature_entry_macros.h',
+        'flags_ui/flags_state.cc',
+        'flags_ui/flags_state.h',
+        'flags_ui/flags_storage.h',
         'flags_ui/flags_ui_constants.cc',
         'flags_ui/flags_ui_constants.h',
         'flags_ui/flags_ui_pref_names.cc',
         'flags_ui/flags_ui_pref_names.h',
-        'flags_ui/flags_storage.h',
         'flags_ui/pref_service_flags_storage.cc',
         'flags_ui/pref_service_flags_storage.h',
       ],
     },
+    {
+      # GN version: //components/flags_ui:switches
+      # This is a separate target so that the dependencies of
+      # //chrome/common can be kept minimal.
+      'target_name': 'flags_ui_switches',
+      'type': 'static_library',
+      'include_dirs': [
+        '..',
+      ],
+      'sources': [
+        # Note: sources list duplicated in GN build.
+        'flags_ui/flags_ui_switches.cc',
+        'flags_ui/flags_ui_switches.h',
+      ],
+    },
+  ],
+  'conditions': [
+    ['OS=="win" and target_arch=="ia32"', {
+      'targets': [
+        {
+          # The flags_ui_switches_win64 target here allows us to use base for
+          # Win64 targets (the normal build is 32 bits).
+          'target_name': 'flags_ui_switches_win64',
+          'type': 'static_library',
+          'include_dirs': [
+            '..',
+          ],
+          'sources': [
+            # Note: sources list duplicated in GN build.
+            'flags_ui/flags_ui_switches.cc',
+            'flags_ui/flags_ui_switches.h',
+          ],
+          'configurations': {
+            'Common_Base': {
+              'msvs_target_platform': 'x64',
+            },
+          },
+        },
+      ],
+    }],
   ],
 }