[Sync] InvalidationService shouldn't CHECK when registering ObjectId for more than one handler

components/invalidation/invalidation_notifier.h

Index: components/invalidation/invalidation_notifier.h
diff --git a/components/invalidation/invalidation_notifier.h b/components/invalidation/invalidation_notifier.h
index 1b0bbda73ed1298f627b6262b82604d9f0d5a8df..112ff6420cb0fc8a28adc30b34573d2dc6201cfb 100644
--- a/components/invalidation/invalidation_notifier.h
+++ b/components/invalidation/invalidation_notifier.h
@@ -54,7 +54,7 @@ class INVALIDATION_EXPORT_PRIVATE InvalidationNotifier
 
   // Invalidator implementation.
   void RegisterHandler(InvalidationHandler* handler) override;
-  void UpdateRegisteredIds(InvalidationHandler* handler,
+  bool UpdateRegisteredIds(InvalidationHandler* handler,
                            const ObjectIdSet& ids) override;
   void UnregisterHandler(InvalidationHandler* handler) override;
   InvalidatorState GetInvalidatorState() const override;