Added base template for config ui.

appengine/config_service/ui/bower_components/shadycss/examples/custom-style-element.js

+/**
+@license
+Copyright (c) 2016 The Polymer Project Authors. All rights reserved.
+This code may only be used under the BSD style license found at http://polymer.github.io/LICENSE.txt
+The complete set of authors may be found at http://polymer.github.io/AUTHORS.txt
+The complete set of contributors may be found at http://polymer.github.io/CONTRIBUTORS.txt
+Code distributed by Google as part of the polymer project is also
+subject to an additional IP rights grant found at http://polymer.github.io/PATENTS.txt
+*/
+
+/*
+Wrapper over <style> elements to co-operate with ShadyCSS
+
+Example:
+<custom-style>
+  <style>
+  ...
+  </style>
+</custom-style>
+*/
+(function() {
+  'use strict';
+
+  const CustomStyleInterface = window.ShadyCSS.CustomStyleInterface;
+
+  class CustomStyle extends HTMLElement {
+    constructor() {
+      super();
+      this._style = null;
+      CustomStyleInterface.addCustomStyle(this);
+    }
+    getStyle() {
+      if (!this._style) {
+        this._style = this.querySelector('style');
+      }
+      return this._style;
+    }
+  }
+
+  window.CustomStyle = CustomStyle;
+  window.customElements.define('custom-style', CustomStyle);
+})();