Update to use one less proxy per element

test/src/common/polymer_descriptor_test.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.
 @TestOn('browser')
 library polymer.test.src.common.polymer_descriptor_test;
 
 import 'dart:js';
 import 'package:test/test.dart';
 import 'package:polymer/polymer.dart';
 import 'package:polymer/src/common/polymer_descriptor.dart';
@@ skipping 50 matching lines @@
     expect(descriptor['attached'] is JsFunction, isTrue);
     expect(descriptor['detached'] is JsFunction, isTrue);
     expect(descriptor['handleSomeEvent'] is JsFunction, isTrue);
     expect(descriptor['myDoubleChanged'] is JsFunction, isTrue);
     expect(descriptor['myNumsCombined'] is JsFunction, isTrue);
     // From the dart behaviors!
     expect(descriptor['behaviorOneExposedMethod'] is JsFunction, isTrue);
     expect(descriptor['behaviorTwoExposedMethod'] is JsFunction, isTrue);
 
     expect(descriptor['behaviors'], isNotNull);
-    expect(descriptor['behaviors'].length, 4);
-    expect(descriptor['behaviors'][0], context['Foo']['JsBehaviorOne']);
-    expect(descriptor['behaviors'][1], behavior.getBehavior(DartBehaviorOne));
-    expect(descriptor['behaviors'][2], context['Foo']['JsBehaviorTwo']);
-    expect(descriptor['behaviors'][3], behavior.getBehavior(DartBehaviorTwo));
-    expect(descriptor['behaviors'][1], isNot(descriptor['behaviors'][3]));
+    expect(descriptor['behaviors'].length, 5);
+    expect(descriptor['behaviors'][0], context['Polymer']['Dart']['Behavior']);
+    expect(descriptor['behaviors'][1], context['Foo']['JsBehaviorOne']);
+    expect(descriptor['behaviors'][2], behavior.getBehavior(DartBehaviorOne));
+    expect(descriptor['behaviors'][3], context['Foo']['JsBehaviorTwo']);
+    expect(descriptor['behaviors'][4], behavior.getBehavior(DartBehaviorTwo));
+    expect(descriptor['behaviors'][2], isNot(descriptor['behaviors'][3]));
   });
 }
 
 @BehaviorProxy(const ['Foo', 'JsBehaviorOne'])
 class JsBehaviorOne {}
 
 @BehaviorProxy(const ['Foo', 'JsBehaviorTwo'])
 class JsBehaviorTwo {}
 
 @behavior
@@ skipping 103 matching lines @@
   expectEqual(actual, expected);
 }
 
 void expectEqual(JsObject actual, Map expected) {
   expect(actual, isNotNull);
   var keys = context['Object'].callMethod('keys', [actual]);
   for (var key in keys) {
     expect(actual[key], equals(expected[key]));
   }
 }