Add a type on lazyAsJsDate

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 303 matching lines @@
   }
 
   static String stringConcatUnchecked(String string1, String string2) {
     return JS_STRING_CONCAT(string1, string2);
   }
 
   static String flattenString(String str) {
     return JS('String', "#.charCodeAt(0) == 0 ? # : #", str, str, str);
   }
 
-  static String getTimeZoneName(receiver) {
+  static String getTimeZoneName(DateTime receiver) {
     // Firefox and Chrome emit the timezone in parenthesis.
     // Example: "Wed May 16 2012 21:13:00 GMT+0200 (CEST)".
     // We extract this name using a regexp.
     var d = lazyAsJsDate(receiver);
     List match = JS('JSArray|Null', r'/\((.*)\)/.exec(#.toString())', d);
     if (match != null) return match[1];
 
     // Internet Explorer 10+ emits the zone name without parenthesis:
     // Example: Thu Oct 31 14:07:44 PDT 2013
     match = JS('JSArray|Null',
@@ skipping 13 matching lines @@
 
     // IE 9 and Opera don't provide the zone name. We fall back to emitting the
     // UTC/GMT offset.
     // Example (IE9): Wed Nov 20 09:51:00 UTC+0100 2013
     //       (Opera): Wed Nov 20 2013 11:03:38 GMT+0100
     match = JS('JSArray|Null', r'/(?:GMT|UTC)[+-]\d{4}/.exec(#.toString())', d);
     if (match != null) return match[0];
     return "";
   }
 
-  static int getTimeZoneOffsetInMinutes(receiver) {
+  static int getTimeZoneOffsetInMinutes(DateTime receiver) {
     // Note that JS and Dart disagree on the sign of the offset.
     return -JS('int', r'#.getTimezoneOffset()', lazyAsJsDate(receiver));
   }
 
   static valueFromDecomposedDate(years, month, day, hours, minutes, seconds,
                                  milliseconds, isUtc) {
     final int MAX_MILLISECONDS_SINCE_EPOCH = 8640000000000000;
     checkInt(years);
     checkInt(month);
     checkInt(day);
@@ skipping 24 matching lines @@
     var date = JS('', r'new Date(#)', value);
     if (isUtc) {
       JS('num', r'#.setUTCFullYear(#)', date, years);
     } else {
       JS('num', r'#.setFullYear(#)', date, years);
     }
     return JS('num', r'#.valueOf()', date);
   }
 
   // Lazily keep a JS Date stored in the JS object.
-  static lazyAsJsDate(receiver) {
+  static lazyAsJsDate(DateTime receiver) {
     if (JS('bool', r'#.date === (void 0)', receiver)) {
       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.
@@ skipping 450 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';
 }