[iOS/GN] Define targets to application extensions resources.

ios/chrome/today_extension/BUILD.gn

+# Copyright 2016 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.
+
+import("//build/config/locales.gni")
+import("//ios/chrome/extension_repack.gni")
+
+group("resources") {
+  deps = [
+    "//ios/chrome/today_extension/strings",
+  ]
+}
+
+extension_repack_all_locales("packed_resources") {
+  extension = "today_extension"
+  input_locales = ios_packed_locales
+  output_locales = ios_packed_locales_as_mac_outputs
+}