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

components/invalidation/non_blocking_invalidator.h

Index: components/invalidation/non_blocking_invalidator.h
diff --git a/components/invalidation/non_blocking_invalidator.h b/components/invalidation/non_blocking_invalidator.h
index 0ca081af26fac9aaf45e94b4ca3910c6cd9a40d5..73db2802c1179652af5cc16fb1e5c622e6249d97 100644
--- a/components/invalidation/non_blocking_invalidator.h
+++ b/components/invalidation/non_blocking_invalidator.h
@@ -55,7 +55,7 @@ class INVALIDATION_EXPORT_PRIVATE NonBlockingInvalidator
 
   // 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;