[third_party] add polymer 1.2.3

polymer_1.2.3/paper-behaviors/demo/paper-button.html

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 @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
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 <link rel="import" href="../../polymer/polymer.html">
 <link rel="import" href="../../paper-material/paper-material.html">
 <link rel="import" href="../paper-button-behavior.html">
 
 <dom-module id="paper-button">
 
   <style>
 
     :host {
       display: inline-block;
+      position: relative;
       background-color: #4285F4;
       color: #fff;
       border-radius: 3px;
       text-transform: uppercase;
       outline: none;
       -moz-user-select: none;
       -ms-user-select: none;
       -webkit-user-select: none;
       user-select: none;
       cursor: pointer;
@@ skipping 31 matching lines @@
       is: 'paper-button',
 
       behaviors: [
         Polymer.PaperButtonBehavior
       ]
     });
 
   </script>
 
 </dom-module>