Modified unittest to use new argument syntax.

tests/html/postmessage_structured_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('postmessage_js_test');
 #import('../../pkg/unittest/unittest.dart');
 #import('../../pkg/unittest/html_config.dart');
 #import('dart:html');
 #import('dart:coreimpl');  // SplayTreeMap
 #import('utils.dart');
@@ skipping 16 matching lines @@
         window.postMessage({eggs: 3}, '*');
         """;
       var callback;
       var onSuccess = expectAsync1((e) {
           window.on.message.remove(callback);
         });
       callback = (e) {
         guardAsync(() {
             var data = e.data;
             if (data is String) return;    // Messages from unit test protocol.
-            expect(data is Map);
+            expect(data, isMap);
             expect(data['eggs'], equals(3));
             onSuccess(e);
           });
       };
       window.on.message.add(callback);
       injectSource(JS_CODE);
     });
 
   test('dart-to-js-to-dart-postmessage', () {
       // Pass dictionaries between Dart and JavaScript.
@@ skipping 11 matching lines @@
         }
         """;
       var callback;
       var onSuccess = expectAsync1((e) {
           window.on.message.remove(callback);
         });
       callback = (e) {
         guardAsync(() {
             var data = e.data;
             if (data is String) return;    // Messages from unit test protocol.
-            expect(data is Map);
+            expect(data, isMap);
             if (data['recipient'] != 'DART') return;  // Hearing the sent message.
             expect(data['peas'], equals(50));
             onSuccess(e);
           });
       };
       window.on.message.add(callback);
       injectSource(JS_CODE);
       window.postMessage({'recipient': 'JS', 'curry': 'peas'}, '*');
     });
 
@@ skipping 11 matching lines @@
               var response = {recipient: 'DART', data: data.data};
               window.removeEventListener('message', handler);
               window.postMessage(response, '*');
             }
             """;
           var onSuccess = expectAsync0(() {});
           callback(e) {
             guardAsync(() {
                 var data = e.data;
                 if (data is String) return;    // Messages from unit test protocol.
-                expect(data is Map);
+                expect(data, isMap);
                 if (data['recipient'] != 'DART') return;  // Not for me.
                 var returnedValue = data['data'];
 
                 window.on.message.remove(callback);
                 expect(returnedValue, isNot(same(value)));
                 verifyGraph(value, returnedValue);
                 onSuccess();
               });
           };
           window.on.message.add(callback);
@@ skipping 19 matching lines @@
   go('test_map', obj1);
   go('test_DAG', obj2);
   go('test_cycle', obj3);
   go('test_simple_splay', obj4);
   go('const_array_1', const [const [1], const [2]]);
   go('const_array_dag', const [const [1], const [1]]);
   go('array_deferred_copy', [1,2,3, obj3, obj3, 6]);
   go('array_deferred_copy_2', [1,2,3, [4, 5, obj3], [obj3, 6]]);
   go('cyclic_list', cyclic_list);
 }