Adding streams to dart:html.

tools/dom/templates/html/dartium/indexed_db_dartium.darttemplate

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 // DO NOT EDIT
 // Auto-generated dart:indexed_db library.
 
 library indexed_db;
 
+import 'dart:async';
 import 'dart:html';
 import 'dart:html_common';
 import 'dart:nativewrappers';
 
 $!GENERATED_DART_FILES
 
 class _KeyRangeFactoryProvider {
 
   static KeyRange createKeyRange_only(/*IDBKey*/ value) =>
       KeyRange.only_(value);
 
   static KeyRange createKeyRange_lowerBound(
       /*IDBKey*/ bound, [bool open = false]) =>
       KeyRange.lowerBound_(bound, open);
 
   static KeyRange createKeyRange_upperBound(
       /*IDBKey*/ bound, [bool open = false]) =>
       KeyRange.upperBound_(bound, open);
 
   static KeyRange createKeyRange_bound(
       /*IDBKey*/ lower, /*IDBKey*/ upper,
       [bool lowerOpen = false, bool upperOpen = false]) =>
       KeyRange.bound_(lower, upper, lowerOpen, upperOpen);
 }