- Move the Timer interface to the dart:isolate library so that it

utils/tests/pub/version_solver_test.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.
 
 #library('pub_update_test');
 
 #import('dart:io');
+#import('dart:isolate');
 
 #import('../../pub/package.dart');
 #import('../../pub/pubspec.dart');
 #import('../../pub/source.dart');
 #import('../../pub/source_registry.dart');
 #import('../../pub/version.dart');
 #import('../../pub/version_solver.dart');
 #import('../../../lib/unittest/unittest.dart');
 
 final noVersion = 'no version';
@@ skipping 250 matching lines @@
 }
 
 Future fakeAsync(callback()) {
   var completer = new Completer();
   new Timer(0, (_) {
     completer.complete(callback());
   });
 
   return completer.future;
 }