MD Settings: Restore message shown when no "zoom" exceptions exist.

chrome/browser/resources/settings/site_settings/zoom_levels.html

 <link rel="import" href="chrome://resources/html/polymer.html">
 <link rel="import" href="chrome://resources/cr_elements/icons.html">
 <link rel="import" href="chrome://resources/polymer/v1_0/paper-icon-button/paper-icon-button.html">
 <link rel="import" href="chrome://resources/html/web_ui_listener_behavior.html">
 <link rel="import" href="../i18n_setup.html">
 <link rel="import" href="../settings_shared_css.html">
 <link rel="import" href="site_settings_behavior.html">
 <link rel="import" href="site_settings_prefs_browser_proxy.html">
 
 <dom-module id="zoom-levels">
   <template>
     <style include="settings-shared">
       :host {
         display: block;
       }
 
       .zoom-label {
         -webkit-margin-end: 16px;
         color: var(--paper-grey-600);
       }
 
-      .empty-message {
+      #empty {
         margin-top: 15px;
       }
     </style>
     <div class="list-frame vertical-list" id="listContainer">
-      <template is="dom-repeat" items="[[sites_]]" id="list"
-          rendered-item-count="{{renderedCount}}">
+      <template is="dom-repeat" items="[[sites_]]" id="list">
         <div class="list-item">
           <div class="favicon-image"
               style$="[[computeSiteIcon(item.originForFavicon)]]">
           </div>
           <div class="middle">
             <div>[[item.displayName]]</div>
           </div>
           <div class="zoom-label">[[item.zoom]]</div>
           <div>
             <paper-icon-button icon="cr:clear" on-tap="removeZoomLevel_"
                 title="$i18n{siteSettingsRemoveZoomLevel}"></paper-icon-button>
           </div>
         </div>
       </template>
-      <template is="dom-if" if="{{!renderedCount}}">
-        <div class="empty-message" id="empty">
+      <template is="dom-if" if="[[!sites_.length]]">
+        <div id="empty">
           $i18n{siteSettingsNoZoomedSites}
         </div>
       </template>
     </div>
   </template>
   <script src="zoom_levels.js"></script>
 </dom-module>