a few small refactorings to closure workarounds

lib/runtime/dart/indexed_db.js

 dart_library.library('dart/indexed_db', null, /* Imports */[
   'dart/_runtime',
   'dart/core',
   'dart/html_common',
   'dart/_js_helper',
+  'dart/async',
   'dart/_interceptors',
-  'dart/async',
   'dart/_metadata',
   'dart/html'
 ], /* Lazy imports */[
-], function(exports, dart, core, html_common, _js_helper, _interceptors, async, _metadata, html) {
+], function(exports, dart, core, html_common, _js_helper, async, _interceptors, _metadata, html) {
   'use strict';
   let dartx = dart.dartx;
   class _KeyRangeFactoryProvider extends core.Object {
     static createKeyRange_only(value) {
       return _KeyRangeFactoryProvider._only(_KeyRangeFactoryProvider._class(), _KeyRangeFactoryProvider._translateKey(value));
     }
     static createKeyRange_lowerBound(bound, open) {
       if (open === void 0) open = false;
       return _KeyRangeFactoryProvider._lowerBound(_KeyRangeFactoryProvider._class(), _KeyRangeFactoryProvider._translateKey(bound), open);
     }
@@ skipping 1096 matching lines @@
   exports.Database = Database;
   exports.IdbFactory = IdbFactory;
   exports.Index = Index;
   exports.KeyRange = KeyRange;
   exports.ObjectStore = ObjectStore;
   exports.Request = Request;
   exports.OpenDBRequest = OpenDBRequest;
   exports.Transaction = Transaction;
   exports.VersionChangeEvent = VersionChangeEvent;
 });