Modified unittest to use new argument syntax.

tests/html/unknownelement_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('UnknownElementTest');
 #import('../../pkg/unittest/unittest.dart');
 #import('../../pkg/unittest/html_config.dart');
 #import('dart:html');
 
 main() {
   useHtmlConfiguration();
 
+  var isUnknownElement =
+      predicate((x) => x is UnknownElement, 'is an UnknownELement');
+
   var foo = new Element.tag('foo');
   foo.id = 'foo';
   var bar = new Element.tag('bar');
   bar.id = 'bar';
   document.body.nodes.addAll([foo, bar]);
 
   test('type-check', () {
-      expect(foo is UnknownElement, isTrue);
-      expect(bar is UnknownElement, isTrue);
+      expect(foo, isUnknownElement);
+      expect(bar, isUnknownElement);
       expect(query('#foo'), equals(foo));
       expect(query('#bar'), equals(bar));
     });
 
   test('dispatch-fail', () {
       expect(() => foo.method1(), throwsNoSuchMethodError);
       expect(() => foo.field1, throwsNoSuchMethodError);
       expect(() { foo.field1 = 42; }, throwsNoSuchMethodError);
     });
 
@@ skipping 31 matching lines @@
 
       expect(foo.x, equals(42));
       expect(() { foo.x = 7; }, throwsNoSuchMethodError);
       expect(foo.id, equals('foo'));
       expect(() => bar.x, throwsNoSuchMethodError);
       bar.y = 11;
       expect(bar.y, equals(11));
       expect(foo.baz('hello'), equals('foo - hello'));
     });
 }