Execute callbacks from JS in the correct zone

tests/html/js_test.dart

 // Copyright (c) 2013, 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 jsTest;
 
 import 'dart:async';
 import 'dart:html';
 import 'dart:typed_data' show ByteBuffer, Int32List;
 import 'dart:indexed_db' show IdbFactory, KeyRange;
@@ skipping 210 matching lines @@
   Color._(this._value);
   String toJs() => this._value;
 }
 
 class TestDartObject {}
 
 class Callable {
   call() => 'called';
 }
 
+typedef ThreeArgFunction(a, b, c);
+
 main() {
   _injectJs();
   useHtmlConfiguration();
 
   group('identity', () {
 
     test('context instances should be identical', () {
       var c1 = context;
       var c2 = context;
       expect(identical(c1, c2), isTrue);
@@ skipping 411 matching lines @@
   group('Dart functions', () {
     test('invoke Dart callback from JS', () {
       expect(() => context.callMethod('invokeCallback'), throws);
 
       context['callback'] = () => 42;
       expect(context.callMethod('invokeCallback'), equals(42));
 
       context.deleteProperty('callback');
     });
 
+    test('invoke Dart callback from JS in a Zone', () {
+      expect(() => context.callMethod('invokeCallback'), throws);
+
+      var childZone = Zone.current.fork();
+      childZone.run(() {
+        context['callback'] = () {
+          expect(Zone.current, childZone);
+        };
+      });
+      context.callMethod('invokeCallback');
+
+      context.deleteProperty('callback');
+    });
+
     test('callback as parameter', () {
       expect(context.callMethod('getTypeOf', [context['razzle']]),
           equals("function"));
     });
 
     test('invoke Dart callback from JS with this', () {
       // A JavaScript constructor function implemented in Dart which
       // uses 'this'
       final constructor = new JsFunction.withThis(($this, arg1) {
         var t = $this;
@@ skipping 15 matching lines @@
       expect(result, 42);
     });
 
     test('emulated functions should be callable in JS', () {
       context['callable'] = new Callable();
       var result = context.callMethod('callable');
       expect(result, 'called');
       context.deleteProperty('callable');
     });
 
+    test('Dart closures should survive a round-trip to JS', () {
+      context['callback'] = (a, b, c) => a + b + c;
+      var f = context['callback'];
+      expect(f, new isInstanceOf<ThreeArgFunction>());
+      context.deleteProperty('callback');
+    });
+
   });
 
   group('JsObject.jsify()', () {
 
     test('convert a List', () {
       final list = [1, 2, 3, 4, 5, 6, 7, 8];
       var array = new JsObject.jsify(list);
       expect(context.callMethod('isArray', [array]), isTrue);
       expect(array['length'], equals(list.length));
       for (var i = 0; i < list.length ; i++) {
@@ skipping 298 matching lines @@
           // expect(context.callMethod('isPropertyInstanceOf', ['o', listType]),
           //    isTrue);
           context.deleteProperty('o');
         }
       });
 
     });
   });
 
 }