arc: Revamp the ArcBridgeService interface

chrome/browser/chromeos/arc/arc_policy_bridge.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 CHROME_BROWSER_CHROMEOS_ARC_ARC_POLICY_BRIDGE_H_
 #define CHROME_BROWSER_CHROMEOS_ARC_ARC_POLICY_BRIDGE_H_
 
 #include "base/macros.h"
 #include "components/arc/arc_bridge_service.h"
 #include "components/arc/arc_service.h"
+#include "components/arc/instance_holder.h"
 #include "components/policy/core/common/policy_service.h"
 #include "mojo/public/cpp/bindings/binding.h"
 
 namespace policy {
 class PolicyMap;
 }  // namespace policy
 
 namespace arc {
 
 // Constants for the ARC certs sync mode are defined in the policy, please keep
 // its in sync.
 enum ArcCertsSyncMode : int32_t {
   // Certificates sync is disabled.
   SYNC_DISABLED = 0,
   // Copy of CA certificates is enabled.
   COPY_CA_CERTS = 1
 };
 
 class ArcPolicyBridge : public ArcService,
-                        public ArcBridgeService::Observer,
+                        public InstanceHolder<mojom::PolicyInstance>::Observer,
                         public mojom::PolicyHost,
                         public policy::PolicyService::Observer {
  public:
   explicit ArcPolicyBridge(ArcBridgeService* bridge_service);
   ArcPolicyBridge(ArcBridgeService* bridge_service,
                   policy::PolicyService* policy_service);
   ~ArcPolicyBridge() override;
 
   void OverrideIsManagedForTesting(bool is_managed);
 
-  // ArcBridgeService::Observer overrides.
-  void OnPolicyInstanceReady() override;
-  void OnPolicyInstanceClosed() override;
+  // InstanceHolder<mojom::PolicyInstance>::Observer overrides.
+  void OnInstanceReady() override;
+  void OnInstanceClosed() override;
 
   // PolicyHost overrides.
   void GetPolicies(const GetPoliciesCallback& callback) override;
 
   // PolicyService::Observer overrides.
   void OnPolicyUpdated(const policy::PolicyNamespace& ns,
                        const policy::PolicyMap& previous,
                        const policy::PolicyMap& current) override;
 
  private:
   void InitializePolicyService();
 
   mojo::Binding<PolicyHost> binding_;
   policy::PolicyService* policy_service_ = nullptr;
   bool is_managed_ = false;
 
   DISALLOW_COPY_AND_ASSIGN(ArcPolicyBridge);
 };
 
 }  // namespace arc
 
 #endif  // CHROME_BROWSER_CHROMEOS_ARC_ARC_POLICY_BRIDGE_H_