Index: sync/notifier/ack_tracker.cc |
diff --git a/sync/notifier/ack_tracker.cc b/sync/notifier/ack_tracker.cc |
index 759b8699508d35d9b0fa1e5ac1c831f02f1e0fda..6461571749c2b57cf307e1e428dfdf2aebc4349e 100644 |
--- a/sync/notifier/ack_tracker.cc |
+++ b/sync/notifier/ack_tracker.cc |
@@ -97,6 +97,7 @@ void AckTracker::Clear() { |
void AckTracker::Track(const ObjectIdSet& ids) { |
DCHECK(thread_checker_.CalledOnValidThread()); |
+ DCHECK(!ids.empty()); |
scoped_ptr<Entry> entry(new Entry( |
create_backoff_entry_callback_.Run(&kDefaultBackoffPolicy), ids)); |