Remove hack for handling accessibility action on ARC notifications.

ui/arc/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.
 
 import("//build/config/ui.gni")
 import("//testing/test.gni")
 
 static_library("arc") {
   sources = [
     "notification/arc_custom_notification_item.cc",
     "notification/arc_custom_notification_item.h",
     "notification/arc_custom_notification_view.cc",
     "notification/arc_custom_notification_view.h",
     "notification/arc_notification_item.cc",
     "notification/arc_notification_item.h",
     "notification/arc_notification_manager.cc",
     "notification/arc_notification_manager.h",
     "notification/arc_notification_surface_manager.cc",
     "notification/arc_notification_surface_manager.h",
   ]
 
   deps = [
     "//ash",
     "//base",
     "//components/arc:arc_base",
     "//components/exo",
     "//components/signin/core/account_id",
     "//mojo/common:common_base",
     "//skia",
+    "//ui/accessibility",
     "//ui/aura",
     "//ui/base",
     "//ui/compositor",
     "//ui/display",
     "//ui/events",
     "//ui/gfx",
     "//ui/message_center",
     "//ui/resources",
     "//ui/strings",
     "//ui/views",
@@ skipping 11 matching lines @@
   deps = [
     ":arc",
     "//base",
     "//base/test:test_support",
     "//components/arc:arc_test_support",
     "//mojo/edk/system",
     "//testing/gtest",
     "//ui/message_center:test_support",
   ]
 }