[Sync] Register USS types with ModelTypeRegistry before download

sync/sessions/model_type_registry.cc

Index: sync/sessions/model_type_registry.cc
diff --git a/sync/sessions/model_type_registry.cc b/sync/sessions/model_type_registry.cc
index 97ace6e7481b2db6149807da11e60fb9c3531e79..f80f69307d6b3418b47f32e3673431c206250b89 100644
--- a/sync/sessions/model_type_registry.cc
+++ b/sync/sessions/model_type_registry.cc
@@ -86,11 +86,15 @@ void ModelTypeRegistry::SetEnabledDirectoryTypes(
   directory_update_handlers_.clear();
   directory_commit_contributors_.clear();
 
+  enabled_directory_types_.Clear();
+
   // Create new ones and add them to the appropriate containers.
   for (ModelSafeRoutingInfo::const_iterator routing_iter = routing_info.begin();
        routing_iter != routing_info.end(); ++routing_iter) {
     ModelType type = routing_iter->first;
     ModelSafeGroup group = routing_iter->second;
+    if (group == GROUP_NON_BLOCKING)
+      continue;
     std::map<ModelSafeGroup, scoped_refptr<ModelSafeWorker> >::iterator
         worker_it = workers_map_.find(group);
     DCHECK(worker_it != workers_map_.end());
@@ -126,9 +130,9 @@ void ModelTypeRegistry::SetEnabledDirectoryTypes(
     bool inserted2 =
         commit_contributor_map_.insert(std::make_pair(type, committer)).second;
     DCHECK(inserted2) << "Attempt to override existing type handler in map";
+    enabled_directory_types_.Put(type);
   }
 
-  enabled_directory_types_ = GetRoutingInfoTypes(routing_info);
   DCHECK(Intersection(GetEnabledDirectoryTypes(),
                       GetEnabledNonBlockingTypes()).Empty());
 }
@@ -291,13 +295,13 @@ void ModelTypeRegistry::OnEncryptionStateChanged() {
 }
 
 ModelTypeSet ModelTypeRegistry::GetEnabledNonBlockingTypes() const {
-  ModelTypeSet enabled_off_thread_types;
+  ModelTypeSet enabled_non_blocking_types;
   for (ScopedVector<syncer_v2::ModelTypeWorker>::const_iterator it =
            model_type_workers_.begin();
        it != model_type_workers_.end(); ++it) {
-    enabled_off_thread_types.Put((*it)->GetModelType());
+    enabled_non_blocking_types.Put((*it)->GetModelType());
   }
-  return enabled_off_thread_types;
+  return enabled_non_blocking_types;
 }
 
 }  // namespace syncer