Modified unittest to use new argument syntax.

tests/html/document_test.dart

Index: tests/html/document_test.dart
===================================================================
--- tests/html/document_test.dart	(revision 14114)
+++ tests/html/document_test.dart	(working copy)
@@ -8,9 +8,11 @@
 
   test('CreateElement', () {
     // FIXME: nifty way crashes, do it boring way.
-    Expect.isTrue(new Element.tag('span') is Element);
-    Expect.isTrue(new Element.tag('div') is DivElement);
-    Expect.isTrue(new Element.tag('a') is AnchorElement);
-    Expect.isTrue(new Element.tag('bad_name') is UnknownElement);
+    expect(new Element.tag('span'), new isInstanceOf<Element>('Element'));
+    expect(new Element.tag('div'), new isInstanceOf<DivElement>('DivElement'));
+    expect(new Element.tag('a'),
+        new isInstanceOf<AnchorElement>('AnchorElement'));
+    expect(new Element.tag('bad_name'),
+        new isInstanceOf<Element>(' is UnknownElement'));
   });
 }