Add 'X' button to 'Manage search engines' tab order.

chrome/browser/resources/options/search_engine_manager_engine_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.
 
 /**
  * @typedef {{canBeDefault: boolean,
  *            canBeEdited: boolean,
  *            canBeRemoved: boolean,
  *            default: boolean,
  *            displayName: string,
@@ skipping 93 matching lines @@
         engine.keyword = '';
         engine.url = '';
       }
 
       this.currentlyValid_ = !this.isPlaceholder;
 
       if (engine.default)
         this.classList.add('default');
 
       this.deletable = engine.canBeRemoved;
+      this.closeButtonElement.tabIndex = 0;
 
       // Construct the name column.
       var nameColEl = this.ownerDocument.createElement('div');
       nameColEl.className = 'name-column';
       nameColEl.classList.add('weakrtl');
       this.contentElement.appendChild(nameColEl);
 
       // Add the favicon.
       var faviconDivEl = this.ownerDocument.createElement('div');
       faviconDivEl.className = 'favicon';
@@ skipping 241 matching lines @@
     },
   };
 
   // Export
   return {
     SearchEngineList: SearchEngineList
   };
 
 });