Implement Invalidator::Acknowledge

sync/notifier/invalidation_notifier.cc

Index: sync/notifier/invalidation_notifier.cc
diff --git a/sync/notifier/invalidation_notifier.cc b/sync/notifier/invalidation_notifier.cc
index 1b9830b40081b93aa40d9bc67cb28555201b3654..7fa0d13c6cb993d86e3c95d08fdf828e439a8f84 100644
--- a/sync/notifier/invalidation_notifier.cc
+++ b/sync/notifier/invalidation_notifier.cc
@@ -52,6 +52,12 @@ void InvalidationNotifier::UnregisterHandler(InvalidationHandler* handler) {
   registrar_.UnregisterHandler(handler);
 }
 
+void InvalidationNotifier::Acknowledge(const invalidation::ObjectId& id,
+                                       const AckHandle& ack_handle) {
+  DCHECK(CalledOnValidThread());
+  invalidation_listener_.Acknowledge(id, ack_handle);
+}
+
 InvalidatorState InvalidationNotifier::GetInvalidatorState() const {
   DCHECK(CalledOnValidThread());
   return registrar_.GetInvalidatorState();