arc: Revamp the ArcBridgeService interface

ui/arc/notification/arc_notification_manager.h

Index: ui/arc/notification/arc_notification_manager.h
diff --git a/ui/arc/notification/arc_notification_manager.h b/ui/arc/notification/arc_notification_manager.h
index f75b8286b7e1a07f6f585a8547e595394e29a3e1..61d8dea0738a61cbef48ce010a6503f902aea6ea 100644
--- a/ui/arc/notification/arc_notification_manager.h
+++ b/ui/arc/notification/arc_notification_manager.h
@@ -19,9 +19,10 @@ namespace arc {
 
 class ArcNotificationItem;
 
-class ArcNotificationManager : public ArcService,
-                               public ArcBridgeService::Observer,
-                               public mojom::NotificationsHost {
+class ArcNotificationManager
+    : public ArcService,
+      public ArcBridgeService::InstanceObserver<mojom::NotificationsInstance>,
+      public mojom::NotificationsHost {
  public:
   ArcNotificationManager(ArcBridgeService* bridge_service,
                          const AccountId& main_profile_id);
@@ -32,9 +33,11 @@ class ArcNotificationManager : public ArcService,
 
   ~ArcNotificationManager() override;
 
-  // ArcBridgeService::Observer implementation:
-  void OnNotificationsInstanceReady() override;
-  void OnNotificationsInstanceClosed() override;
+  // ArcBridgeService::InstanceObserver<mojom::NotificationsInstance>
+  // implementation:
+  void OnInstanceReady(mojom::NotificationsInstance* notifications_instance,
+                       uint32_t version) override;
+  void OnInstanceClosed(mojom::NotificationsInstance*) override;
 
   // mojom::NotificationsHost implementation:
   void OnNotificationPosted(mojom::ArcNotificationDataPtr data) override;
@@ -45,8 +48,8 @@ class ArcNotificationManager : public ArcService,
   // Methods called from ArcNotificationItem:
   void SendNotificationRemovedFromChrome(const std::string& key);
   void SendNotificationClickedOnChrome(const std::string& key);
-  void SendNotificationButtonClickedOnChrome(
-      const std::string& key, int button_index);
+  void SendNotificationButtonClickedOnChrome(const std::string& key,
+                                             int button_index);
 
  private:
   const AccountId main_profile_id_;