Make element.style["color"] work in Sky

sky/engine/bindings/scripts/templates/interface_dart.template

 // Copyright 2015 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 // WARNING: Do not edit - generated code.
 part of sky.core;
 
 {% macro args_macro(args) -%}
     {%- for arg in args -%}
         {%- if arg.is_optional and (loop.first or not args[arg.index-1].is_optional) -%}
@@ skipping 25 matching lines @@
     {{ attribute.dart_type }} get {{ attribute.name }} native "{{interface_name}}_{{ attribute.name }}_Getter";
 {% if not attribute.is_read_only %}
     void set {{ attribute.name }}({{ attribute.dart_type }} value) native "{{interface_name}}_{{ attribute.name }}_Setter";
 {% endif %}
 {% endfor %}
 
     // Methods
 {% for method in methods %}
     {{method.dart_type}} {{method.name}}({{ args_macro(method.arguments)}}) native "{{interface_name}}_{{ method.name }}_Callback";
 {% endfor %}
+
+    // Operators
+{% if named_property_getter %}
+    String operator[](String name) native "{{interface_name}}___getter___Callback";
+{% endif %}
+{% if named_property_setter %}
+    void operator[]=(String name, String value) native "{{interface_name}}___setter___Callback";
+{% endif %}
 }