Clear old ARC instance before opt-in.

components/arc/arc_service_manager.cc

Index: components/arc/arc_service_manager.cc
diff --git a/components/arc/arc_service_manager.cc b/components/arc/arc_service_manager.cc
index 7666577c38a165de5958d4a256fd5ade7395d573..dc57044ef2cf17567676bdaa5a7968c0db7bfea1 100644
--- a/components/arc/arc_service_manager.cc
+++ b/components/arc/arc_service_manager.cc
@@ -98,11 +98,13 @@ void ArcServiceManager::AddService(std::unique_ptr<ArcService> service) {
 
 void ArcServiceManager::OnPrimaryUserProfilePrepared(
     const AccountId& account_id,
-    std::unique_ptr<BooleanPrefMember> arc_enabled_pref) {
+    std::unique_ptr<BooleanPrefMember> arc_enabled_pref,
+    PrefService* pref_service) {
   DCHECK(thread_checker_.CalledOnValidThread());
 
   AddService(base::WrapUnique(new ArcUserDataService(
-      arc_bridge_service(), std::move(arc_enabled_pref), account_id)));
+      arc_bridge_service(), std::move(arc_enabled_pref), pref_service,
+      account_id)));
 
   AddService(base::WrapUnique(
       new ArcNotificationManager(arc_bridge_service(), account_id)));