Move the supervised user error page to a component

components/supervised_user_error_page/BUILD.gn

 # Copyright 2014 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.
 
-static_library("network_time") {
+source_set("supervised_user_error_page") {
   sources = [
-    "network_time_pref_names.cc",
-    "network_time_pref_names.h",
-    "network_time_tracker.cc",
-    "network_time_tracker.h",
+    "supervised_user_error_page.cc",
+    "supervised_user_error_page.h",
   ]
 
   deps = [
     "//base",
-    "//base:i18n",
-    "//components/prefs",
+    "//components/resources",
+    "//components/strings",
+    "//ui/base",
   ]
 }
 
 source_set("unit_tests") {
   testonly = true
   sources = [
-    "network_time_tracker_unittest.cc",
+    "supervised_user_error_page_unittest.cc",
   ]
-
   deps = [
-    ":network_time",
+    ":supervised_user_error_page",
     "//base",
     "//base/test:test_support",
-    "//components/prefs:test_support",
+    "//components/resources",
+    "//components/strings",
+    "//testing/gmock",
     "//testing/gtest",
   ]
 }