[Sheriff-o-matic] Remove race condition on the commit list.

Tools/GardeningServer/ui/ct-commit-list.html

 <!--
 Copyright 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.
 -->
 
 <link rel="import" href="ct-commit.html">
 <link rel="import" href="../bower_components/paper-button/paper-button.html">
 
 <polymer-element name="ct-commit-list" attributes="commitList">
   <template>
     <style>
       :host {
         display: block;
       }
       paper-icon-button {
         vertical-align: middle;
       }
       .repository-info {
         display: block;
       }
     </style>
-    <template repeat="{{ repository in commitList | _repositories }}">
+    <template repeat="{{ repository in commitList.repositories }}">
       <div class="repository-info">
         {{ repository.name }} {{ repository.range }}
         <paper-icon-button icon="unfold-more"
             on-click="{{ _toggle }}" repository="{{ repository.name }}"></paper-icon-button>
         <template if="{{ repository.expanded }}">
           <template repeat="{{ commit in repository.commits }}">
             <ct-commit data="{{ commit }}"></ct-commit>
           </template>
         </template>
       </div>
     </template>
   </template>
   <script>
   Polymer({
-    repositories: undefined,
-
-    created: function() {
-      this.repositories = [];
-    },
-
-    _repositories: function() {
-      if (this.commitList)
-        this.repositories = this.commitList.repositories();
-      return this.repositories;
-    },
-
     _toggle: function(event, detail, sender, target) {
       var repo = sender.getAttribute('repository');
-      var r = this.repositories.find(function(item) {
+      var r = this.commitList.repositories.find(function(item) {
         return item.name === repo;
       });
       r.expanded = !r.expanded;
     }
   });
   </script>
 </polymer-element>