Add ArcEnabled policy implementation

components/arc/arc_service_manager.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_ARC_SERVICE_MANAGER_H_
 #define COMPONENTS_ARC_ARC_SERVICE_MANAGER_H_
 
 #include <vector>
 
 #include "base/macros.h"
@@ skipping 20 matching lines @@
   // Adds a service to the managed services list.
   void AddService(scoped_ptr<ArcService> service);
 
   // Gets the global instance of the ARC Service Manager. This can only be
   // called on the thread that this class was created on.
   static ArcServiceManager* Get();
 
   // Called when the main profile is initialized after user logs in.
   void OnPrimaryUserProfilePrepared(const AccountId& account_id);
 
+  // Set ArcBridgeService instance for testing. Call before ArcServiceManager
+  // creation. ArcServiceManager owns |arc_bridge_service|.
+  static void SetArcBridgeServiceForTesting(
+      scoped_ptr<ArcBridgeService> arc_bridge_service);
  private:
   base::ThreadChecker thread_checker_;
   scoped_ptr<ArcBridgeService> arc_bridge_service_;
   std::vector<scoped_ptr<ArcService>> services_;
 
   DISALLOW_COPY_AND_ASSIGN(ArcServiceManager);
 };
 
 }  // namespace arc
 
 #endif  // COMPONENTS_ARC_ARC_SERVICE_MANAGER_H_