components: Add GN Build files for component_updater and user_manager.

components/user_manager/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.
+
+component("user_manager") {
+  sources = [
+    "empty_user_info.cc",
+    "empty_user_info.h",
+    "user_info.cc",
+    "user_info.h",
+    "user_info_impl.cc",
+    "user_info_impl.h",
+    "user_manager_export.h",
+  ]
+
+  if (is_chromeos) {
+    sources += [
+      "user_image/user_image.cc",
+      "user_image/user_image.h",
+      "user_type.h",
+    ]
+  }
+
+  defines = [
+    "USER_MANAGER_IMPLEMENTATION",
+  ]
+
+  deps = [
+    "//base",
+    "//skia",
+    "//ui/gfx",
+    "//url",
+  ]
+}