Missed two files that needed dart:async import.

pkg/intl/lib/date_symbol_data_http_request.dart

 // 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.
 
 /**
  * This file should be imported, along with date_format.dart in order to read
  * locale data via http requests to a web server..
  */
 library date_symbol_data_json;
 
-import "date_symbols.dart";
-import "src/lazy_locale_data.dart";
+import 'dart:async';
+import 'date_symbols.dart';
+import 'src/lazy_locale_data.dart';
 import 'src/date_format_internal.dart';
 import 'src/http_request_data_reader.dart';
 
 part "src/data/dates/localeList.dart";
 
 /**
  * This should be called for at least one [locale] before any date formatting
  * methods are called. It sets up the lookup for date symbols using [url].
  * The [url] parameter should end with a "/". For example,
  *   "http://localhost:8000/dates/"
  */
 Future initializeDateFormatting(String locale, String url) {
   var reader = new HTTPRequestDataReader('${url}symbols/');
   initializeDateSymbols(() => new LazyLocaleData(
       reader, _createDateSymbol, availableLocalesForDateFormatting));
   var reader2 = new HTTPRequestDataReader('${url}patterns/');
   initializeDatePatterns(() => new LazyLocaleData(
       reader2, (x) => x, availableLocalesForDateFormatting));
   return initializeIndividualLocaleDateFormatting(
       (symbols, patterns) {
         return Futures.wait([
             symbols.initLocale(locale),
             patterns.initLocale(locale)]);
       });
 }
 
 /** Defines how new date symbol entries are created. */
 DateSymbols _createDateSymbol(Map map) {
   return new DateSymbols.deserializeFromMap(map);
-}
+}