Modified unittest to use new argument syntax.

tests/html/blob_constructor_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('blob_test');
 #import('../../pkg/unittest/unittest.dart');
 #import('../../pkg/unittest/html_config.dart');
 #import('dart:html');
 
 main() {
   useHtmlConfiguration();
 
   test('basic', () {
       var b = new Blob([]);
-      expect(b.size, 0);
+      expect(b.size, isZero);
     });
 
   test('type1', () {
       // OPTIONALS var b = new Blob(['Harry'], type: 'text');
       var b = new Blob(['Harry'], 'text');
       expect(b.size, 5);
       expect(b.type, 'text');
     });
 
   test('endings1', () {
       // OPTIONALS var b = new Blob(['A\nB\n'], endings: 'transparent');
       var b = new Blob(['A\nB\n'], null, 'transparent');
       expect(b.size, 4);
     });
 
   test('endings2', () {
       // OPTIONALS var b = new Blob(['A\nB\n'], endings: 'native');
       var b = new Blob(['A\nB\n'], null, 'native');
-      expect(b.size, (x) => x == 4 || x == 6);
+      expect(b.size, (x) => x == 4 || x == 6,
+          reason: "b.size should be 4 or 6");
     });
 
   test('twoStrings', () {
       // OPTIONALS var b = new Blob(['123', 'xyz'], type: 'text/plain;charset=UTF-8');
       var b = new Blob(['123', 'xyz'], 'text/plain;charset=UTF-8');
       expect(b.size, 6);
     });
 
   test('fromBlob1', () {
       var b1 = new Blob([]);
       var b2 = new Blob([b1]);
-      expect(b2.size, 0);
+      expect(b2.size, isZero);
     });
 
   test('fromBlob2', () {
       var b1 = new Blob(['x']);
       var b2 = new Blob([b1, b1]);
       expect(b1.size, 1);
       expect(b2.size, 2);
     });
 
   test('fromArrayBuffer', () {
       var a = new Uint8Array(100).buffer; // i.e. new ArrayBuffer(100);
       var b = new Blob([a, a]);
       expect(b.size, 200);
     });
 }