Implemented UI for the meetings controller out-of-box.

chrome/browser/resources/chromeos/login/oobe-screen.js

 // Copyright (c) 2014 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.
 
 Polymer('oobe-screen', (function() {
   /** @const */ var CALLBACK_USER_ACTED = 'userActed';
 
   function doNothing() {};
 
   return {
@@ skipping 33 matching lines @@
     initialize: doNothing,
 
     ready: function() {
       if (this.decorate_) {
         this.initialize();
       } else {
         this.ready_ = true;
       }
     },
 
+    userActed: function(_, _, source) {
+      this.send(CALLBACK_USER_ACTED, source.getAttribute('action'));
+    },
+
     i18n: function(args) {
       if (!(args instanceof Array))
         args = [args];
       args[0] = 'login_' + this.name + '_' + args[0];
       return loadTimeData.getStringF.apply(loadTimeData, args);
     },
 
     /**
      * Called by login.Screen when the screen is beeing registered.
      */
     decorate: function(screen) {
       this.screen_ = screen;
       screen.initialize();
       this.context = screen.screenContext_;
       this.C = this.context.storage_;
       this.contextObservers_ = {};
       var self = this;
-      this.querySelectorAllImpl_('button[action]').forEach(function(button) {
-        button.addEventListener('click', function(e) {
-          var action = this.getAttribute('action');
-          self.send(CALLBACK_USER_ACTED, action);
-          e.stopPropagation();
-        });
-      });
       if (this.ready_) {
         this.initialize();
       } else {
         this.decorate_ = true;
       }
     },
 
     /**
      * @final
      */
@@ skipping 122 matching lines @@
      */
     getPropertyNameOf_: function(value) {
       for (var key in this)
         if (this[key] === value)
           return key;
       return '';
     }
   };
 })());