Add the new content widget including localised title.

ios/chrome/content_widget_extension/strings/BUILD.gn

+# Copyright 2017 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("//tools/grit/grit_rule.gni")
+
+group("strings") {
+  public_deps = [
+    ":ios_content_widget_extension_chromium_strings",
+    ":ios_content_widget_extension_google_chrome_strings",
+  ]
+}
+
+grit("ios_content_widget_extension_chromium_strings") {
+  source = "ios_content_widget_extension_chromium_strings.grd"
+  output_dir = "$root_gen_dir/ios/content_widget_extension"
+  outputs = [
+    "grit/ios_content_widget_extension_chromium_strings.h",
+  ]
+  foreach(locale, locales_with_fake_bidi) {
+    outputs += [ "ios_content_widget_extension_chromium_strings_$locale.pak" ]
+  }
+}
+
+grit("ios_content_widget_extension_google_chrome_strings") {
+  source = "ios_content_widget_extension_google_chrome_strings.grd"
+  output_dir = "$root_gen_dir/ios/content_widget_extension"
+  outputs = [
+    "grit/ios_content_widget_extension_google_chrome_strings.h",
+  ]
+  foreach(locale, locales_with_fake_bidi) {
+    outputs +=
+        [ "ios_content_widget_extension_google_chrome_strings_$locale.pak" ]
+  }
+}