Componentize internal class FlagsState in flags_ui component.

components/BUILD.gn

Index: components/BUILD.gn
diff --git a/components/BUILD.gn b/components/BUILD.gn
index 6eb0dfb75a0f552f162e4a4bf8c6b8ed7409386c..504cef5a68cc1c7565244b6412de49bdca84a775 100644
--- a/components/BUILD.gn
+++ b/components/BUILD.gn
@@ -28,17 +28,18 @@ group("all_components") {
     "//components/data_reduction_proxy/core/browser",
     "//components/data_reduction_proxy/core/common",
     "//components/device_event_log",
+    "//components/flags_ui",
     "//components/google/core/browser",
+    "//components/infobars/core",
+    "//components/leveldb_proto",
+    "//components/omnibox/browser",
+    "//components/pref_registry",
     "//components/search",
     "//components/search_engines",
     "//components/sessions",
+    "//components/strings",
     "//components/sync_bookmarks",
     "//components/undo",
-    "//components/strings",
-    "//components/leveldb_proto",
-    "//components/pref_registry",
-    "//components/omnibox/browser",
-    "//components/infobars/core",
     "//components/version_ui",
   ]
 
@@ -314,20 +315,21 @@ test("components_unittests") {
     "//components/content_settings/core/common",
     "//components/data_usage/core:unit_tests",
     "//components/data_use_measurement/content:unit_tests",
+    "//components/flags_ui:unit_tests",
     "//components/google/core/browser:unit_tests",
+    "//components/leveldb_proto:unit_tests",
     "//components/net_log:unit_tests",
+    "//components/omnibox/browser:unit_tests",
     "//components/search:unit_tests",
+    "//components/search_engines:unit_tests",
     "//components/sessions:unit_tests",
+    "//components/suggestions:unit_tests",
     "//components/syncable_prefs:unit_tests",
     "//components/undo:unit_tests",
+    "//components/undo:unit_tests",
     "//net",
     "//ui/base",
     "//ui/resources:ui_test_pak",
-    "//components/search_engines:unit_tests",
-    "//components/undo:unit_tests",
-    "//components/leveldb_proto:unit_tests",
-    "//components/suggestions:unit_tests",
-    "//components/omnibox/browser:unit_tests",
   ]
 
   if (!is_ios) {