Fix for Back navigation keyboard shortcut does not work properly for chrome://settings/cookies.

chrome/browser/resources/options/cookies_list.js

 // Copyright (c) 2012 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.
 
 cr.define('options', function() {
   /** @const */ var DeletableItemList = options.DeletableItemList;
   /** @const */ var DeletableItem = options.DeletableItem;
   /** @const */ var ArrayDataModel = cr.ui.ArrayDataModel;
   /** @const */ var ListSingleSelectionModel = cr.ui.ListSingleSelectionModel;
 
@@ skipping 716 matching lines @@
     },
 
     /**
      * Handles key down events and looks for left and right arrows, then
      * dispatches to the currently expanded item, if any.
      * @param {Event} e The keydown event.
      * @private
      */
     handleKeyLeftRight_: function(e) {
       var id = e.keyIdentifier;
+      if (e.altKey || e.ctrlKey || e.metaKey || e.shiftKey)
+        return;
       if ((id == 'Left' || id == 'Right') && this.expandedItem) {
         var cs = this.ownerDocument.defaultView.getComputedStyle(this);
         var rtl = cs.direction == 'rtl';
         if ((!rtl && id == 'Left') || (rtl && id == 'Right'))
           this.expandedItem.selectedIndex--;
         else
           this.expandedItem.selectedIndex++;
         this.scrollIndexIntoView(this.expandedItem.listIndex);
         // Prevent the page itself from scrolling.
         e.preventDefault();
@@ skipping 179 matching lines @@
       parent.endBatchUpdates();
     },
   };
 
   return {
     CookiesList: CookiesList,
     CookieListItem: CookieListItem,
     CookieTreeNode: CookieTreeNode,
   };
 });