fixed #579, make DateTime use in the SDK typed

tool/input_sdk/private/js_helper.dart

 // Copyright (c) 2013, 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.
 
 library dart._js_helper;
 
 import 'dart:collection';
 
 import 'dart:_foreign_helper' show
     JS,
@@ skipping 394 matching lines @@
       JS('void', r'#.date = new Date(#)', receiver,
          receiver.millisecondsSinceEpoch);
     }
     return JS('var', r'#.date', receiver);
   }
 
   // The getters for date and time parts below add a positive integer to ensure
   // that the result is really an integer, because the JavaScript implementation
   // may return -0.0 instead of 0.
 
-  static getYear(receiver) {
+  static getYear(DateTime receiver) {
     return (receiver.isUtc)
       ? JS('int', r'(#.getUTCFullYear() + 0)', lazyAsJsDate(receiver))
       : JS('int', r'(#.getFullYear() + 0)', lazyAsJsDate(receiver));
   }
 
-  static getMonth(receiver) {
+  static getMonth(DateTime receiver) {
     return (receiver.isUtc)
       ? JS('int', r'#.getUTCMonth() + 1', lazyAsJsDate(receiver))
       : JS('int', r'#.getMonth() + 1', lazyAsJsDate(receiver));
   }
 
-  static getDay(receiver) {
+  static getDay(DateTime receiver) {
     return (receiver.isUtc)
       ? JS('int', r'(#.getUTCDate() + 0)', lazyAsJsDate(receiver))
       : JS('int', r'(#.getDate() + 0)', lazyAsJsDate(receiver));
   }
 
-  static getHours(receiver) {
+  static getHours(DateTime receiver) {
     return (receiver.isUtc)
       ? JS('int', r'(#.getUTCHours() + 0)', lazyAsJsDate(receiver))
       : JS('int', r'(#.getHours() + 0)', lazyAsJsDate(receiver));
   }
 
-  static getMinutes(receiver) {
+  static getMinutes(DateTime receiver) {
     return (receiver.isUtc)
       ? JS('int', r'(#.getUTCMinutes() + 0)', lazyAsJsDate(receiver))
       : JS('int', r'(#.getMinutes() + 0)', lazyAsJsDate(receiver));
   }
 
-  static getSeconds(receiver) {
+  static getSeconds(DateTime receiver) {
     return (receiver.isUtc)
       ? JS('int', r'(#.getUTCSeconds() + 0)', lazyAsJsDate(receiver))
       : JS('int', r'(#.getSeconds() + 0)', lazyAsJsDate(receiver));
   }
 
-  static getMilliseconds(receiver) {
+  static getMilliseconds(DateTime receiver) {
     return (receiver.isUtc)
       ? JS('int', r'(#.getUTCMilliseconds() + 0)', lazyAsJsDate(receiver))
       : JS('int', r'(#.getMilliseconds() + 0)', lazyAsJsDate(receiver));
   }
 
-  static getWeekday(receiver) {
+  static getWeekday(DateTime receiver) {
     int weekday = (receiver.isUtc)
       ? JS('int', r'#.getUTCDay() + 0', lazyAsJsDate(receiver))
       : JS('int', r'#.getDay() + 0', lazyAsJsDate(receiver));
     // Adjust by one because JS weeks start on Sunday.
     return (weekday + 6) % 7 + 1;
   }
 
   static valueFromDateString(str) {
     if (str is !String) throw argumentErrorValue(str);
     var value = JS('num', r'Date.parse(#)', str);
@@ skipping 396 matching lines @@
   // we have no way of telling the compiler yet, so it will generate an extra
   // layer of indirection that wraps the SyncIterator.
   _jsIterator() => JS('', '#(...#)', _generator, _args);
 
   Iterator<E> get iterator => new SyncIterator<E>(_jsIterator());
 }
 
 class BooleanConversionAssertionError extends AssertionError {
   toString() => 'Failed assertion: boolean expression must not be null';
 }