Remove usage of dart:json.

tools/dom/src/Isolates.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.
 
 part of html;
 
 _serialize(var message) {
   return new _JsSerializer().traverse(message);
 }
 
@@ skipping 82 matching lines @@
     return _deserialize(result);
   }
 
   static _call(int isolateId, int portId, var message) {
     var target = 'dart-port-$isolateId-$portId';
     // TODO(vsm): Make this re-entrant.
     // TODO(vsm): Set this up set once, on the first call.
     var source = '$target-result';
     var result = null;
     window.on[source].first.then((Event e) {
-      result = json.parse(_getPortSyncEventData(e));
+      result = JSON.decode(_getPortSyncEventData(e));
     });
     _dispatchEvent(target, [source, message]);
     return result;
   }
 
   bool operator==(var other) {
     return (other is _RemoteSendPortSync) && (_isolateId == other._isolateId)
       && (_portId == other._portId);
   }
 
@@ skipping 63 matching lines @@
   }
 
   static String _getListenerName(isolateId, portId) =>
       'dart-port-$isolateId-$portId';
   String get _listenerName => _getListenerName(_isolateId, _portId);
 
   void receive(callback(var message)) {
     _callback = callback;
     if (_portSubscription == null) {
       _portSubscription = window.on[_listenerName].listen((Event e) {
-        var data = json.parse(_getPortSyncEventData(e));
+        var data = JSON.decode(_getPortSyncEventData(e));
         var replyTo = data[0];
         var message = _deserialize(data[1]);
         var result = _callback(message);
         _dispatchEvent(replyTo, _serialize(result));
       });
     }
   }
 
   void close() {
     _portMap.remove(_portId);
@@ skipping 10 matching lines @@
     } else {
       return new _RemoteSendPortSync(isolateId, portId);
     }
   }
 }
 
 get _isolateId => ReceivePortSync._isolateId;
 
 void _dispatchEvent(String receiver, var message) {
   var event = new CustomEvent(receiver, canBubble: false, cancelable:false,
-    detail: json.stringify(message));
+    detail: JSON.encode(message));
   window.dispatchEvent(event);
 }
 
 String _getPortSyncEventData(CustomEvent event) => event.detail;