arc-bridge: Introduce the ArcService class

ui/arc/notification/arc_notification_manager.h

 // 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.
 
 #ifndef UI_ARC_NOTIFICATION_ARC_NOTIFICATION_MANAGER_H_
 #define UI_ARC_NOTIFICATION_ARC_NOTIFICATION_MANAGER_H_
 
 #include <map>
 #include <string>
 
 #include "base/containers/scoped_ptr_hash_map.h"
 #include "components/arc/arc_bridge_service.h"
+#include "components/arc/arc_service.h"
 #include "components/arc/common/notifications.mojom.h"
 #include "components/signin/core/account_id/account_id.h"
 #include "mojo/public/cpp/bindings/binding.h"
 
 namespace arc {
 
 class ArcNotificationItem;
 
-class ArcNotificationManager : public ArcBridgeService::Observer,
+class ArcNotificationManager : public ArcService,
+                               public ArcBridgeService::Observer,
                                public NotificationsHost {
  public:
   ArcNotificationManager(ArcBridgeService* bridge_service,
                          const AccountId& main_profile_id);
   ~ArcNotificationManager() override;
 
   // ArcBridgeService::Observer implementation:
   void OnNotificationsInstanceReady() override;
 
   // NotificationsHost implementation:
   void OnNotificationPosted(ArcNotificationDataPtr data) override;
   void OnNotificationRemoved(const mojo::String& key) override;
 
   // Methods called from ArcNotificationItem:
   void SendNotificationRemovedFromChrome(const std::string& key);
   void SendNotificationClickedOnChrome(const std::string& key);
 
  private:
-  ArcBridgeService* const arc_bridge_;
   const AccountId main_profile_id_;
 
   using ItemMap =
       base::ScopedPtrHashMap<std::string, scoped_ptr<ArcNotificationItem>>;
   ItemMap items_;
 
   mojo::Binding<arc::NotificationsHost> binding_;
 
   DISALLOW_COPY_AND_ASSIGN(ArcNotificationManager);
 };
 
 }  // namespace arc
 
 #endif  // UI_ARC_NOTIFICATION_ARC_NOTIFICATION_MANAGER_H_