Adds AppListDelegate to AppList that is notified on visibility changes

ash/BUILD.gn

 # Copyright 2014 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/features.gni")
 import("//build/config/ui.gni")
 import("//testing/test.gni")
 import("//ui/base/ui_features.gni")
 
 # Historical note: Ash shipped on Windows for a couple years to support
 # Windows 8 Metro mode. Windows support was removed in 2016.
 assert(is_chromeos)
 assert(use_aura)
 assert(enable_hidpi)
 
 component("ash") {
   sources = [
     "accelerators/accelerator_commands_aura.cc",
     "accelerators/accelerator_commands_aura.h",
     "accelerators/accelerator_controller_delegate_aura.cc",
     "accelerators/accelerator_controller_delegate_aura.h",
     "accelerators/accelerator_delegate.cc",
     "accelerators/accelerator_delegate.h",
     "accelerators/key_hold_detector.cc",
     "accelerators/key_hold_detector.h",
     "accelerators/magnifier_key_scroller.cc",
     "accelerators/magnifier_key_scroller.h",
     "accelerators/spoken_feedback_toggler.cc",
     "accelerators/spoken_feedback_toggler.h",
+    "app_list/app_list_delegate_impl.cc",
+    "app_list/app_list_delegate_impl.h",
     "app_list/app_list_presenter_delegate.cc",
     "app_list/app_list_presenter_delegate.h",
     "app_list/app_list_presenter_delegate_factory.cc",
     "app_list/app_list_presenter_delegate_factory.h",
     "ash_export.h",
     "ash_touch_exploration_manager_chromeos.cc",
     "ash_touch_exploration_manager_chromeos.h",
     "aura/aura_layout_manager_adapter.cc",
     "aura/aura_layout_manager_adapter.h",
     "aura/key_event_watcher_aura.cc",
@@ skipping 1385 matching lines @@
     "//content/public/app:both",
     "//device/bluetooth",
   ]
 
   data_deps = [
     "//ash/common/strings:ash_test_strings",
     "//ash/resources:ash_test_resources_with_content_100_percent",
     "//ash/resources:ash_test_resources_200_percent",
   ]
 }