First cut at behaviors. This just implements the lifecycle methodsportion. We may get the rest for …

lib/src/common/polymer_mixin.dart

 // Copyright (c) 2014, 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 polymer.src.common.polymer_js_proxy;
 
 import 'dart:html';
 import 'dart:js';
 import 'package:polymer_interop/polymer_interop.dart' show Polymer, PolymerDom;
+import 'package:web_components/web_components.dart';
 import 'js_proxy.dart';
 
 
 /// Basic api for re-using the polymer js prototypes.
-abstract class PolymerMixin implements JsProxy {
+abstract class PolymerMixin implements JsProxy, CustomElementProxyMixin {
   JsObject _proxy;
 
   JsObject get jsElement {
     if (_proxy == null) {
       _proxy = new JsObject.fromBrowserObject(this);
       _proxy['__data__'] = jsProxy;
     }
     return _proxy;
   }
 
@@ skipping 189 matching lines @@
         throw 'All elements on path $path must be annoted with '
           '@jsProxyReflectable, `${parts.length[i - 1]}` was not.';
       }
       obj = mirror.invokeGetter(parts[i]);
     }
     return obj;
   }
 }
 
 class Foo extends Object with Polymer, Polymer, Polymer {}