Handle storyboards in GN.

ios/chrome/app/resources/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/chrome_build.gni")
 import("//build/config/ios/rules.gni")
 import("//build/config/locales.gni")
 import("//ios/chrome/app/resources/ios_chrome_repack.gni")
 import("//ios/public/provider/chrome/browser/build_config.gni")
 import("//tools/grit/grit_rule.gni")
@@ skipping 89 matching lines @@
     "launchscreen_images.xcassets/launchscreen_app_logo.imageset/Contents.json",
     "launchscreen_images.xcassets/launchscreen_app_logo.imageset/launchscreen_app_logo.png",
     "launchscreen_images.xcassets/launchscreen_brand_name.imageset/Contents.json",
     "launchscreen_images.xcassets/launchscreen_brand_name.imageset/launchscreen_brand_name.png",
   ]
   outputs = [
     "{{bundle_resources_dir}}/{{source_file_part}}",
   ]
 }
 
-bundle_data_xib("launchscreen_xib") {
+bundle_data_ib_file("launchscreen_xib") {
   source = "LaunchScreen.xib"
   deps = [
     ios_launchscreen_assets_target,
   ]
 }