Update to use one less proxy per element

lib/src/common/polymer_descriptor.dart

 // Copyright (c) 2015, 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.micro.properties;
 
 import 'dart:js';
 import 'package:reflectable/reflectable.dart';
 import 'behavior.dart';
 import 'declarations.dart';
 import 'js_proxy.dart';
@@ skipping 224 matching lines @@
           _throwInvalidMixinOrder(type, clazz);
         }
       });
     }
     checkAndRemoveSuperInterfaces(behavior);
 
     // Get the js object for the behavior from the annotation, and add it.
     finalBehaviors.add(behavior);
   }
 
-  return finalBehaviors.map((ClassMirror behavior) {
-    BehaviorAnnotation meta = behavior.metadata.firstWhere(_isBehavior);
-    return meta.getBehavior(behavior.reflectedType);
-  });
+  return <JsObject>[_polymerDart['Behavior']]

[Siggi Cherem (dart-lang), 2015/09/17 21:11:59]

maybe we should rename Polymer.Dart.Behavior to something more self-explanatory?

Ideas:

Polymer.Dart.InteropBehavior
Polymer.Dart.PolymerInteropBehavior
Polymer.Dart.BindingInteropBehavior

alternatively, add a comment here explaining why this behavior is always on by
default.

[jakemac, 2015/09/23 17:37:08]

Changed to InteropBehavior

+    ..addAll(finalBehaviors.map((ClassMirror behavior) {
+      BehaviorAnnotation meta = behavior.metadata.firstWhere(_isBehavior);
+      return meta.getBehavior(behavior.reflectedType);
+    }));
 }
 
 // Throws an error about expected mixins that must precede the [clazz] mixin.
 void _throwInvalidMixinOrder(Type type, ClassMirror mixin) {
   var expected = mixin.superinterfaces
       .where(_hasBehaviorMeta)
       .map((clazz) => clazz.simpleName)
       .join(', ');
   throw 'Unexpected mixin ordering on type $type. The ${mixin.simpleName} mixin '
       'must be  immediately preceded by the following mixins, in this order: '
@@ skipping 22 matching lines @@
     case 'String':
       return context['String'];
     case 'Map':
     case 'JsObject':
       return context['Object'];
     default:
       // Just return the Dart type
       return type;
   }
 }