Clear old ARC instance before opt-in.

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 <memory>
 #include <vector>
 
@@ skipping 26 matching lines @@
   // Adds a service to the managed services list.
   void AddService(std::unique_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,
-      std::unique_ptr<BooleanPrefMember> arc_enabled_pref);
+      std::unique_ptr<BooleanPrefMember> arc_enabled_pref,
+      PrefService* pref_service);
 
   // Called once the windowing system (ash) has been started.
   void OnAshStarted();
 
   // Called to shut down all ARC services.
   void Shutdown();
 
   scoped_refptr<base::TaskRunner> blocking_task_runner() const {
     return blocking_task_runner_;
   }
@@ skipping 23 matching lines @@
   // True once the window manager service got added, barring adding any more
   // of those since OnAshStarted() might be called multiple times.
   bool on_ash_started_called_ = false;
 
   DISALLOW_COPY_AND_ASSIGN(ArcServiceManager);
 };
 
 }  // namespace arc
 
 #endif  // COMPONENTS_ARC_ARC_SERVICE_MANAGER_H_