Revert 150990 - [Sync] Avoid unregistering object IDs on shutdown

sync/notifier/invalidation_notifier.cc

Index: sync/notifier/invalidation_notifier.cc
===================================================================
--- sync/notifier/invalidation_notifier.cc	(revision 150991)
+++ sync/notifier/invalidation_notifier.cc	(working copy)
@@ -36,23 +36,14 @@
   DCHECK(CalledOnValidThread());
 }
 
-void InvalidationNotifier::RegisterHandler(SyncNotifierObserver* handler) {
-  DCHECK(CalledOnValidThread());
-  registrar_.RegisterHandler(handler);
-}
-
 void InvalidationNotifier::UpdateRegisteredIds(SyncNotifierObserver* handler,
                                                const ObjectIdSet& ids) {
   DCHECK(CalledOnValidThread());
-  registrar_.UpdateRegisteredIds(handler, ids);
-  invalidation_client_.UpdateRegisteredIds(registrar_.GetAllRegisteredIds());
+  const ObjectIdSet& all_registered_ids =
+      helper_.UpdateRegisteredIds(handler, ids);
+  invalidation_client_.UpdateRegisteredIds(all_registered_ids);
 }
 
-void InvalidationNotifier::UnregisterHandler(SyncNotifierObserver* handler) {
-  DCHECK(CalledOnValidThread());
-  registrar_.UnregisterHandler(handler);
-}
-
 void InvalidationNotifier::SetUniqueId(const std::string& unique_id) {
   DCHECK(CalledOnValidThread());
   invalidation_client_id_ = unique_id;
@@ -102,18 +93,18 @@
 
 void InvalidationNotifier::OnInvalidate(const ObjectIdPayloadMap& id_payloads) {
   DCHECK(CalledOnValidThread());
-  registrar_.DispatchInvalidationsToHandlers(id_payloads, REMOTE_NOTIFICATION);
+  helper_.DispatchInvalidationsToHandlers(id_payloads, REMOTE_NOTIFICATION);
 }
 
 void InvalidationNotifier::OnNotificationsEnabled() {
   DCHECK(CalledOnValidThread());
-  registrar_.EmitOnNotificationsEnabled();
+  helper_.EmitOnNotificationsEnabled();
 }
 
 void InvalidationNotifier::OnNotificationsDisabled(
     NotificationsDisabledReason reason) {
   DCHECK(CalledOnValidThread());
-  registrar_.EmitOnNotificationsDisabled(reason);
+  helper_.EmitOnNotificationsDisabled(reason);
 }
 
 }  // namespace syncer