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

components/invalidation/fake_invalidator.cc

Index: components/invalidation/fake_invalidator.cc
diff --git a/components/invalidation/fake_invalidator.cc b/components/invalidation/fake_invalidator.cc
index 00bbc87b7afeb4a591637c82cebac2f28e59195b..d82c3972e36173224a87dc9ad3246f62ac242858 100644
--- a/components/invalidation/fake_invalidator.cc
+++ b/components/invalidation/fake_invalidator.cc
@@ -42,9 +42,9 @@ void FakeInvalidator::RegisterHandler(InvalidationHandler* handler) {
   registrar_.RegisterHandler(handler);
 }
 
-void FakeInvalidator::UpdateRegisteredIds(InvalidationHandler* handler,
+bool FakeInvalidator::UpdateRegisteredIds(InvalidationHandler* handler,
                                           const ObjectIdSet& ids) {
-  registrar_.UpdateRegisteredIds(handler, ids);
+  return registrar_.UpdateRegisteredIds(handler, ids);
 }
 
 void FakeInvalidator::UnregisterHandler(InvalidationHandler* handler) {