arc: Revamp the ArcBridgeService interface

components/arc/power/arc_power_bridge.h

Index: components/arc/power/arc_power_bridge.h
diff --git a/components/arc/power/arc_power_bridge.h b/components/arc/power/arc_power_bridge.h
index d82aad664293a37e410527605ab3df16b3f2db4a..77f7318d79605726ddc2cdd6b62401d4635dcc8c 100644
--- a/components/arc/power/arc_power_bridge.h
+++ b/components/arc/power/arc_power_bridge.h
@@ -17,17 +17,19 @@ namespace arc {
 
 // ARC Power Client sets power management policy based on requests from
 // ARC instances.
-class ArcPowerBridge : public ArcService,
-                       public ArcBridgeService::Observer,
-                       public ui::DisplayConfigurator::Observer,
-                       public mojom::PowerHost {
+class ArcPowerBridge
+    : public ArcService,
+      public ArcBridgeService::InstanceObserver<mojom::PowerInstance>,
+      public ui::DisplayConfigurator::Observer,
+      public mojom::PowerHost {
  public:
   explicit ArcPowerBridge(ArcBridgeService* bridge_service);
   ~ArcPowerBridge() override;
 
-  // ArcBridgeService::Observer overrides.
-  void OnPowerInstanceReady() override;
-  void OnPowerInstanceClosed() override;
+  // ArcBridgeService::InstanceObserver<mojom::PowerInstance> overrides.
+  void OnInstanceReady(mojom::PowerInstance* power_instance,
+                       uint32_t version) override;
+  void OnInstanceClosed(mojom::PowerInstance*) override;
 
   // DisplayConfigurator::Observer overrides.
   void OnPowerStateChanged(chromeos::DisplayPowerState power_state) override;