Promotes a handful of members from WmShell to Shell

ui/arc/notification/arc_notification_manager.cc

 // 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.
 
 #include "ui/arc/notification/arc_notification_manager.h"
 
 #include <memory>
 #include <utility>
 
 #include "ash/common/system/toast/toast_manager.h"
-#include "ash/common/wm_shell.h"
+#include "ash/shell.h"
 #include "base/memory/ptr_util.h"
 #include "base/stl_util.h"
 #include "base/strings/utf_string_conversions.h"
 #include "components/arc/arc_bridge_service.h"
 #include "ui/arc/notification/arc_custom_notification_item.h"
 #include "ui/arc/notification/arc_notification_item.h"
 
 namespace arc {
 
 ArcNotificationManager::ArcNotificationManager(ArcBridgeService* bridge_service,
@@ skipping 216 matching lines @@
     return;
 
   notifications_instance->OpenNotificationSettings(key);
 }
 
 void ArcNotificationManager::OnToastPosted(mojom::ArcToastDataPtr data) {
   const base::string16 text16(
       base::UTF8ToUTF16(data->text.has_value() ? *data->text : std::string()));
   const base::string16 dismiss_text16(base::UTF8ToUTF16(
       data->dismiss_text.has_value() ? *data->dismiss_text : std::string()));
-  ash::WmShell::Get()->toast_manager()->Show(
+  ash::Shell::GetInstance()->toast_manager()->Show(
       ash::ToastData(data->id, text16, data->duration, dismiss_text16));
 }
 
 void ArcNotificationManager::OnToastCancelled(mojom::ArcToastDataPtr data) {
-  ash::WmShell::Get()->toast_manager()->Cancel(data->id);
+  ash::Shell::GetInstance()->toast_manager()->Cancel(data->id);
 }
 
 }  // namespace arc