[ObjC ARC] Converts ios/chrome/browser/ui/ntp:ntp_internal to ARC.

ios/chrome/browser/ui/ntp/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.
 
 bundle_data("resources") {
   sources = [
     "resources/bookmarks_bar_bg.png",
     "resources/bookmarks_bar_bg@2x.png",
     "resources/bookmarks_bar_bg@2x~ipad.png",
     "resources/bookmarks_bar_bg_pressed@2x~ipad.png",
@@ skipping 119 matching lines @@
     "//ios/chrome/browser/ui",
     "//ios/chrome/browser/ui/commands",
     "//ios/chrome/browser/ui/toolbar",
     "//ios/chrome/browser/ui/toolbar:resource_macros",
     "//ios/chrome/common",
     "//ui/base",
   ]
 }
 
 source_set("ntp_internal") {
+  configs += [ "//build/config/compiler:enable_arc" ]
   sources = [
     "centering_scrollview.h",
     "centering_scrollview.mm",
     "google_landing_consumer.h",
     "google_landing_mediator.h",
     "google_landing_mediator.mm",
     "google_landing_view_controller.h",
     "google_landing_view_controller.mm",
     "incognito_panel_controller.h",
     "incognito_panel_controller.mm",
     "most_visited_cell.h",
     "most_visited_cell.mm",
     "most_visited_layout.h",
     "most_visited_layout.mm",
     "new_tab_page_bar.h",
     "new_tab_page_bar.mm",
     "new_tab_page_bar_button.h",
     "new_tab_page_bar_button.mm",
     "new_tab_page_bar_item.h",
     "new_tab_page_bar_item.mm",
     "new_tab_page_controller.h",
     "new_tab_page_controller.mm",
+    "new_tab_page_controller_testing.h",
     "new_tab_page_panel_protocol.mm",
     "new_tab_page_view.h",
     "new_tab_page_view.mm",
     "notification_promo_whats_new.h",
     "notification_promo_whats_new.mm",
     "whats_new_header_view.h",
     "whats_new_header_view.mm",
   ]
   public_deps = [
     ":ntp_header",
@@ skipping 133 matching lines @@
     "new_tab_page_perftest.mm",
   ]
   deps = [
     "//base/test:test_support",
     "//ios/chrome/browser/sessions",
     "//ios/chrome/browser/tabs",
     "//ios/chrome/browser/test:perf_test_support",
     "//ios/chrome/browser/ui:ui_internal",
   ]
 }