Upgrade to 1.0 and switch clients to dom-repeat where needed.

third_party/polymer/v0_8/components/paper-styles/default-theme.html

 <!--
-    @license
-    Copyright (c) 2015 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
+@license
+Copyright (c) 2015 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
 -->
 
 <link rel="import" href="../polymer/polymer.html">
 
-<style is="x-style">
+<style is="custom-style">
 
-  * {
+  :root {
 
     --dark-primary-color: #303f9f;
 
     --default-primary-color: #3f51b5;
 
     --light-primary-color: #c5cae9;
 
     --text-primary-color: #ffffff;
 
     --accent-color: #ff4081;
 
     --primary-background-color: #ffffff;
 
     --primary-text-color: #212121;
 
     --secondary-text-color: #757575;
 
     --disabled-text-color: #bdbdbd;
 
     --divider-color: #e0e0e0;
 
   }
 
 </style>