Add support for timezone offset and timezone name.

lib/compiler/implementation/lib/mockimpl.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.
 
 // Mocks of classes and interfaces that Leg cannot read directly.
 
 // TODO(ahe): Remove this file.
 
 class JSSyntaxRegExp implements RegExp {
   final String pattern;
@@ skipping 279 matching lines @@
 
   int hashCode() => value;
 
   Date changeTimeZone(TimeZone targetTimeZone) {
     if (targetTimeZone == null) {
       targetTimeZone = new TimeZoneImplementation.local();
     }
     return new Date.fromEpoch(value, targetTimeZone);
   }
 
+  String get timeZoneName() {
+    if (isUtc()) return "UTC";
+    return Primitives.getTimeZoneName(this);
+  }
+
+  Duration get timeZoneOffset() {
+    if (isUtc()) return new Duration(0);
+    return new Duration(minutes: Primitives.getTimeZoneOffsetInMinutes(this));
+  }
+
   int get year() => Primitives.getYear(this);
 
   int get month() => Primitives.getMonth(this);
 
   int get day() => Primitives.getDay(this);
 
   int get hours() => Primitives.getHours(this);
 
   int get minutes() => Primitives.getMinutes(this);
 
@@ skipping 80 matching lines @@
   factory List.from(Iterable<E> other) {
     List<E> result = new List<E>();
     // TODO(ahe): Use for-in when it is implemented correctly.
     Iterator<E> iterator = other.iterator();
     while (iterator.hasNext()) {
       result.add(iterator.next());
     }
     return result;
   }
 }