[iOS Clean] Created OverlayService.

ios/clean/chrome/test/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("//ios/public/provider/chrome/browser/build_config.gni")
 import("//testing/test.gni")
 
 group("all_tests") {
   testonly = true
   deps = [
     ":ios_clean_chrome_unittests",
   ]
 }
 
 test("ios_clean_chrome_unittests") {
   deps = [
     # Ensure that all unit tests are run, use fake hooks and pack resources.
     "//ios/chrome/test:run_all_unittests",
     ios_packed_resources_target,
 
     # Add unit_tests target here.
     "//ios/clean/chrome/app/steps:unit_tests",
     "//ios/clean/chrome/browser/ui/bookmarks:unit_tests",
     "//ios/clean/chrome/browser/ui/context_menu:unit_tests",
     "//ios/clean/chrome/browser/ui/find_in_page:unit_tests",
     "//ios/clean/chrome/browser/ui/ntp:unit_tests",
     "//ios/clean/chrome/browser/ui/omnibox:unit_tests",
+    "//ios/clean/chrome/browser/ui/overlay_service/internal:unit_tests",
     "//ios/clean/chrome/browser/ui/recent_tabs:unit_tests",
     "//ios/clean/chrome/browser/ui/root:unit_tests",
     "//ios/clean/chrome/browser/ui/tab:unit_tests",
     "//ios/clean/chrome/browser/ui/tab_collection:unit_tests",
     "//ios/clean/chrome/browser/ui/tab_grid:unit_tests",
     "//ios/clean/chrome/browser/ui/toolbar:unit_tests",
     "//ios/clean/chrome/browser/ui/tools:unit_tests",
     "//ios/clean/chrome/browser/ui/web_contents:unit_tests",
   ]
 }