arc: Revamp the ArcBridgeService interface

components/arc/power/arc_power_bridge.h

 // Copyright 2015 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 COMPONENTS_ARC_POWER_ARC_POWER_BRIDGE_H_
 #define COMPONENTS_ARC_POWER_ARC_POWER_BRIDGE_H_
 
 #include <map>
 
 #include "base/macros.h"
 #include "components/arc/arc_bridge_service.h"
 #include "components/arc/arc_service.h"
+#include "components/arc/instance_holder.h"
 #include "mojo/public/cpp/bindings/binding.h"
 #include "ui/display/chromeos/display_configurator.h"
 
 namespace arc {
 
 // ARC Power Client sets power management policy based on requests from
 // ARC instances.
 class ArcPowerBridge : public ArcService,
-                       public ArcBridgeService::Observer,
+                       public InstanceHolder<mojom::PowerInstance>::Observer,
                        public ui::DisplayConfigurator::Observer,
                        public mojom::PowerHost {
  public:
   explicit ArcPowerBridge(ArcBridgeService* bridge_service);
   ~ArcPowerBridge() override;
 
-  // ArcBridgeService::Observer overrides.
-  void OnPowerInstanceReady() override;
-  void OnPowerInstanceClosed() override;
+  // InstanceHolder<mojom::PowerInstance>::Observer overrides.
+  void OnInstanceReady() override;
+  void OnInstanceClosed() override;
 
   // DisplayConfigurator::Observer overrides.
   void OnPowerStateChanged(chromeos::DisplayPowerState power_state) override;
 
   // mojom::PowerHost overrides.
   void OnAcquireDisplayWakeLock(mojom::DisplayWakeLockType type) override;
   void OnReleaseDisplayWakeLock(mojom::DisplayWakeLockType type) override;
 
   void IsDisplayOn(const IsDisplayOnCallback& callback) override;
 
  private:
   void ReleaseAllDisplayWakeLocks();
 
   mojo::Binding<mojom::PowerHost> binding_;
 
   // Stores a mapping of type -> wake lock ID for all wake locks
   // held by ARC.
   std::multimap<mojom::DisplayWakeLockType, int> wake_locks_;
 
   DISALLOW_COPY_AND_ASSIGN(ArcPowerBridge);
 };
 
 }  // namespace arc
 
 #endif  // COMPONENTS_ARC_POWER_ARC_POWER_BRIDGE_H_