[MD History] Use proper shadows for cards.

chrome/browser/resources/md_history/history_list.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-list',
 
   properties: {
     // The search term for the current query. Set when the query returns.
     searchedTerm: {
       type: String,
       value: '',
     },
 
     lastSearchedTerm_: String,
 
     querying: Boolean,
 
     // An array of history entries in reverse chronological order.
     historyData_: Array,
 
     resultLoadingDisabled_: {
       type: Boolean,
       value: false,
     },
   },
 
   listeners: {
-    'infinite-list.scroll': 'notifyListScroll_',
+    'scroll': 'notifyListScroll_',
     'remove-bookmark-stars': 'removeBookmarkStars_',
   },
 
   /** @override */
   attached: function() {
     // It is possible (eg, when middle clicking the reload button) for all other
     // resize events to fire before the list is attached and can be measured.
     // Adding another resize here ensures it will get sized correctly.
     /** @type {IronListElement} */(this.$['infinite-list']).notifyResize();
+    this.$['infinite-list'].scrollTarget = this;
+    this.$['scroll-threshold'].scrollTarget = this;
   },
 
   /**
    * Remove bookmark star for history items with matching URLs.
    * @param {{detail: !string}} e
    * @private
    */
   removeBookmarkStars_: function(e) {
     var url = e.detail;
 
@@ skipping 189 matching lines @@
     return index == 0;
   },
 
   /**
    * @private
    */
   notifyListScroll_: function() {
     this.fire('history-list-scrolled');
   },
 });