Apply new WM shadows to app list.

ui/app_list/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/ui.gni")
 import("//testing/test.gni")
 
 component("app_list") {
   sources = [
     "app_list_constants.cc",
@@ skipping 81 matching lines @@
     deps += [
       "//ui/aura",
       "//ui/wm",
     ]
   }
 
   if (toolkit_views) {
     sources += [
       "views/all_apps_tile_item_view.cc",
       "views/all_apps_tile_item_view.h",
-      "views/app_list_background.cc",
-      "views/app_list_background.h",
       "views/app_list_drag_and_drop_host.h",
       "views/app_list_folder_view.cc",
       "views/app_list_folder_view.h",
       "views/app_list_item_view.cc",
       "views/app_list_item_view.h",
       "views/app_list_main_view.cc",
       "views/app_list_main_view.h",
       "views/app_list_page.cc",
       "views/app_list_page.h",
       "views/app_list_view.cc",
@@ skipping 166 matching lines @@
       "views/speech_view_unittest.cc",
       "views/test/apps_grid_view_test_api.cc",
       "views/test/apps_grid_view_test_api.h",
     ]
     deps += [
       "//ui/views",
       "//ui/views:test_support",
     ]
   }
 }