[ObjC ARC] Converts ios/chrome/browser/native_app_launcher:unit_tests_internal to ARC.

ios/chrome/browser/native_app_launcher/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.
 
 source_set("native_app_launcher") {
   sources = [
     "ios_appstore_ids.h",
     "ios_appstore_ids.mm",
     "native_app_infobar_controller.h",
     "native_app_infobar_controller.mm",
@@ skipping 64 matching lines @@
     "//ios/public/provider/chrome/browser/ui",
     "//ios/web",
     "//net",
     "//ui/base",
     "//url",
   ]
   libs = [ "StoreKit.framework" ]
 }
 
 source_set("unit_tests_internal") {
+  configs += [ "//build/config/compiler:enable_arc" ]
   testonly = true
   sources = [
     "native_app_navigation_controller_unittest.mm",
     "native_app_navigation_util_unittest.mm",
   ]
   deps = [
     ":native_app_launcher",
     ":native_app_launcher_internal",
     "//base",
     "//base/test:test_support",
     "//components/infobars/core",
     "//ios/chrome/browser",
     "//ios/chrome/browser/infobars:infobars",
     "//ios/chrome/browser/web:test_support",
     "//ios/chrome/test:test_support",
     "//ios/public/provider/chrome/browser",
     "//ios/public/provider/chrome/browser:test_support",
     "//ios/public/provider/chrome/browser/native_app_launcher:test_support",
     "//ios/public/provider/chrome/browser/signin:test_support",
     "//ios/web",
     "//ios/web:test_support",
     "//net:test_support",
     "//testing/gmock",
     "//testing/gtest",
     "//ui/base",
     "//url",
   ]
 }