arc: Revamp the ArcBridgeService interface

components/arc/test/fake_policy_instance.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 COMPONENTS_ARC_TEST_FAKE_POLICY_INSTANCE_H_
 #define COMPONENTS_ARC_TEST_FAKE_POLICY_INSTANCE_H_
 
 #include "components/arc/arc_bridge_service.h"
 #include "components/arc/common/policy.mojom.h"
+#include "components/arc/instance_holder.h"
 #include "components/arc/test/fake_arc_bridge_instance.h"
 
 namespace arc {
 
-class FakePolicyInstance : public mojom::PolicyInstance,
-                           public arc::ArcBridgeService::Observer {
+class FakePolicyInstance
+    : public mojom::PolicyInstance,
+      public arc::InstanceHolder<mojom::PolicyInstance>::Observer {
  public:
   // bridge_service should not be destroyed before the destructor is called.
   FakePolicyInstance(mojo::InterfaceRequest<mojom::PolicyInstance> request,
                      ArcBridgeService* bridge_service);
   ~FakePolicyInstance() override;
 
   // mojom::PolicyInstance
   void Init(mojom::PolicyHostPtr host_ptr) override;
   void OnPolicyUpdated() override;
 
-  // arc::ArcBridgeService::Observer
-  void OnPolicyInstanceReady() override;
+  // arc::InstanceHolder<mojom::PolicyInstance>::Observer
+  void OnInstanceReady() override;
 
   void WaitForOnPolicyInstanceReady();
   void CallGetPolicies(const mojom::PolicyHost::GetPoliciesCallback& callback);
 
  private:
   mojo::Binding<mojom::PolicyInstance> binding_;
   ArcBridgeService* const bridge_service_;
   mojom::PolicyHostPtr host_ptr_;
 
   bool ready_ = false;
 
   DISALLOW_COPY_AND_ASSIGN(FakePolicyInstance);
 };
 
 }  // namespace arc
 
 #endif  // COMPONENTS_ARC_TEST_FAKE_POLICY_INSTANCE_H_