[Sync] Convert sessions/ directory to ModelEnumSet

chrome/browser/sync/engine/syncer_proto_util.cc

Index: chrome/browser/sync/engine/syncer_proto_util.cc
diff --git a/chrome/browser/sync/engine/syncer_proto_util.cc b/chrome/browser/sync/engine/syncer_proto_util.cc
index ab6a0b10d4026c32e0eab83297a77bdc675c3be6..ca782f326e6498a2cb02dca26c0b82fdf74baae0 100644
--- a/chrome/browser/sync/engine/syncer_proto_util.cc
+++ b/chrome/browser/sync/engine/syncer_proto_util.cc
@@ -87,9 +87,9 @@ void SyncerProtoUtil::HandleMigrationDoneResponse(
   sessions::SyncSession* session) {
   LOG_IF(ERROR, 0 >= response->migrated_data_type_id_size())
       << "MIGRATION_DONE but no types specified.";
-  syncable::ModelTypeSet to_migrate;
+  syncable::ModelEnumSet to_migrate;
   for (int i = 0; i < response->migrated_data_type_id_size(); i++) {
-    to_migrate.insert(syncable::GetModelTypeFromExtensionFieldNumber(
+    to_migrate.Put(syncable::GetModelTypeFromExtensionFieldNumber(
         response->migrated_data_type_id(i)));
   }
   // TODO(akalin): This should be a set union.