Abort sync cycles when download step fails

sync/engine/apply_updates_command.cc

Index: sync/engine/apply_updates_command.cc
diff --git a/sync/engine/apply_updates_command.cc b/sync/engine/apply_updates_command.cc
index 79fd039ba2312e35e647fb65368b519692482aad..83dfb51696c7f283a5a04fcb9be7bc0ab5b84e8d 100644
--- a/sync/engine/apply_updates_command.cc
+++ b/sync/engine/apply_updates_command.cc
@@ -72,7 +72,8 @@ SyncerError ApplyUpdatesCommand::ModelChangingExecuteImpl(
   // This might be the first time we've fully completed a sync cycle, for
   // some subset of the currently synced datatypes.
   const sessions::StatusController& status(session->status_controller());
-  if (status.ServerSaysNothingMoreToDownload()) {
+  if (status.error().last_download_updates_result == SYNCER_OK
+      && status.updates_response().get_updates().changes_remaining() == 0) {
     for (syncable::ModelTypeSet::Iterator it =
              status.updates_request_types().First(); it.Good(); it.Inc()) {
       // This gets persisted to the directory's backing store.