[MD History] Extract shared stylesheet.

chrome/browser/resources/md_history/history_item.js

 // Copyright 2015 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({
   is: 'history-item',
 
   properties: {
     // The date of these history items.
     historyDate: {
@@ skipping 76 matching lines @@
       countAddition: this.$.checkbox.checked ? 1 : -1
     });
   },
 
   /**
    * When the url for the history-item is set, the icon associated with this
    * website is also set.
    * @private
    */
   showIcon_: function() {
-    this.$['website-icon'].style.backgroundImage =
+    this.$.icon.style.backgroundImage =
         getFaviconImageSet(this.websiteUrl);
   },
 
   /**
    * Fires a custom event when the menu button is clicked. Sends the details of
    * the history item and where the menu should appear.
    */
   onMenuButtonTap_: function(e) {
     var position = this.$['menu-button'].getBoundingClientRect();
 
     this.fire('toggle-menu', {
       x: position.left,
       y: position.top,
       accessTime: this.timestamp
     });
 
     // Stops the 'tap' event from closing the menu when it opens.
     e.stopPropagation();
   },
 
   selectionNotAllowed_: function() {
     return !loadTimeData.getBoolean('allowDeletingHistory');
   }
 });