Big merge from experimental to bleeding edge.

tests/html/xhr_cross_origin_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 XHRCrossOriginTest;
 import '../../pkg/unittest/lib/unittest.dart';
 import '../../pkg/unittest/lib/html_config.dart';
 import 'dart:html';
-import 'dart:json';
+import 'dart:json' as json;
 
 main() {
   useHtmlConfiguration();
 
   test('XHR Cross-domain', () {
     var url = "http://localhost:9876/tests/html/xhr_cross_origin_data.txt";
     var xhr = new HttpRequest();
     xhr.open('GET', url, true);
     var validate = expectAsync1((data) {
       expect(data, contains('feed'));
       expect(data['feed'], contains('entry'));
       expect(data, isMap);
     });
     xhr.on.readyStateChange.add((e) {
       guardAsync(() {
         if (xhr.readyState == HttpRequest.DONE) {
-          validate(JSON.parse(xhr.response));
+          validate(json.parse(xhr.response));
         }
       });
     });
     xhr.send();
   });
 
   test('XHR.get Cross-domain', () {
     var url = "http://localhost:9876/tests/html/xhr_cross_origin_data.txt";
     new HttpRequest.get(url, expectAsync1((xhr) {
-      var data = JSON.parse(xhr.response);
+      var data = json.parse(xhr.response);
       expect(data, contains('feed'));
       expect(data['feed'], contains('entry'));
       expect(data, isMap);
     }));
   });
 }