fix packages for latest SDK changes

pkg/mdv/lib/mdv.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.
 
 // TODO(jmesserly): more commentary here.
 /**
  * This library provides access to Model-Driven-Views APIs on HTML elements.
  * More information can be found at: <https://github.com/toolkitchen/mdv>.
  */
 library mdv;
@@ skipping 18 matching lines @@
 part 'src/template.dart';
 part 'src/template_iterator.dart';
 part 'src/text.dart';
 part 'src/text_area_element.dart';
 
 /** Initialize the Model-Driven Views polyfill. */
 void initialize() {
   TemplateElement.mdvPackage = _mdv;
 }
 
-StreamController<DocumentFragment> _instanceCreated;
+
+typedef DocumentFragmentCreated(DocumentFragment fragment);
+
+// TODO(jmesserly): ideally this would be a stream, but they don't allow
+// reentrancy.
+Set<DocumentFragmentCreated> _instanceCreated;
 
 /**
  * *Warning*: This is an implementation helper for Model-Driven Views and
  * should not be used in your code.
  *
  * This event is fired whenever a template is instantiated via
  * [Element.createInstance].
  */
 // TODO(rafaelw): This is a hack, and is neccesary for the polyfill
 // because custom elements are not upgraded during clone()
 // TODO(jmesserly): polymer removed this in:
 // https://github.com/Polymer/platform/commit/344ffeaae475babb529403f6608588a0fc73f4e7
-Stream<DocumentFragment> get instanceCreated {
+Set<DocumentFragmentCreated> get instanceCreated {
   if (_instanceCreated == null) {
-    _instanceCreated = new StreamController<DocumentFragment>(sync: true);
+    _instanceCreated = new Set<DocumentFragmentCreated>();
   }
-  return _instanceCreated.stream;
+  return _instanceCreated;
 }
 
 
 // TODO(jmesserly): investigate if expandos give us enough performance.
 
 // The expando for storing our MDV wrappers.
 //
 // In general, we need state associated with the nodes. Rather than having a
 // bunch of individual expandos, we keep one per node.
 //
@@ skipping 23 matching lines @@
   } else if (node is Node) {
     wrapper = new _NodeExtension(node);
   } else {
     // TODO(jmesserly): this happens for things like CompoundBinding.
     wrapper = node;
   }
 
   _mdvExpando[node] = wrapper;
   return wrapper;
 }