fix packages for latest SDK changes

pkg/mdv/test/template_element_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 template_element_test;
 
 import 'dart:async';
 import 'dart:collection';
 import 'dart:html';
 import 'dart:math' as math;
@@ skipping 1676 matching lines @@
     TemplateElement.bootstrap(template);
     template2 = template.content.nodes.first;
     expect(template2.content.nodes.length, 2);
     var template3 = template2.content.nodes.first.nextNode;
     expect(template3.content.nodes.length, 1);
     expect(template3.content.nodes.first.text, 'Hello');
   });
 
   observeTest('instanceCreated hack', () {
     var called = false;
-    var sub = mdv.instanceCreated.listen((node) {
+
+    callback(node) {
       called = true;
       expect(node.nodeType, Node.DOCUMENT_FRAGMENT_NODE);
-    });
+    }
+    mdv.instanceCreated.add(callback);
 
     var div = createTestHtml('<template bind="{{}}">Foo</template>');
     expect(called, false);
 
     recursivelySetTemplateModel(div, null);
     performMicrotaskCheckpoint();
     expect(called, true);
 
-    sub.cancel();
+    mdv.instanceCreated.remove(callback);
   });
 }
 
 class TestBindingSyntax extends BindingDelegate {
   getBinding(model, String path, name, node) {
     if (path.trim() == 'replaceme') return new ObservableBox('replaced');
     return null;
   }
 }
 
@@ skipping 50 matching lines @@
       k = k is String ? sym(k) : _deepToSymbol(k);
       result[k] = _deepToSymbol(v);
     });
     return result;
   }
   if (value is Iterable) {
     return value.map(_deepToSymbol).toList();
   }
   return value;
 }