Remove support for the keygen tag

chrome/browser/resources/settings/route.js

 // Copyright 2016 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('settings', function() {
   /**
    * Class for navigable routes. May only be instantiated within this file.
    * @constructor
    * @param {string} path
    * @private
@@ skipping 142 matching lines @@
   r.SITE_SETTINGS_AUTOMATIC_DOWNLOADS =
       r.SITE_SETTINGS.createChild('automaticDownloads');
   r.SITE_SETTINGS_BACKGROUND_SYNC =
       r.SITE_SETTINGS.createChild('backgroundSync');
   r.SITE_SETTINGS_CAMERA = r.SITE_SETTINGS.createChild('camera');
   r.SITE_SETTINGS_COOKIES = r.SITE_SETTINGS.createChild('cookies');
   r.SITE_SETTINGS_DATA_DETAILS =
       r.SITE_SETTINGS_COOKIES.createChild('/cookies/detail');
   r.SITE_SETTINGS_IMAGES = r.SITE_SETTINGS.createChild('images');
   r.SITE_SETTINGS_JAVASCRIPT = r.SITE_SETTINGS.createChild('javascript');
-  r.SITE_SETTINGS_KEYGEN = r.SITE_SETTINGS.createChild('keygen');
   r.SITE_SETTINGS_LOCATION = r.SITE_SETTINGS.createChild('location');
   r.SITE_SETTINGS_MICROPHONE = r.SITE_SETTINGS.createChild('microphone');
   r.SITE_SETTINGS_NOTIFICATIONS = r.SITE_SETTINGS.createChild('notifications');
   r.SITE_SETTINGS_FLASH = r.SITE_SETTINGS.createChild('flash');
   r.SITE_SETTINGS_POPUPS = r.SITE_SETTINGS.createChild('popups');
   r.SITE_SETTINGS_UNSANDBOXED_PLUGINS =
       r.SITE_SETTINGS.createChild('unsandboxedPlugins');
   r.SITE_SETTINGS_USB_DEVICES = r.SITE_SETTINGS.createChild('usbDevices');
   r.SITE_SETTINGS_ZOOM_LEVELS = r.SITE_SETTINGS.createChild('zoomLevels');
   r.SITE_SETTINGS_PDF_DOCUMENTS = r.SITE_SETTINGS.createChild('pdfDocuments');
@@ skipping 211 matching lines @@
     RouteObserverBehavior: RouteObserverBehavior,
     getRouteForPath: getRouteForPath,
     initializeRouteFromUrl: initializeRouteFromUrl,
     getCurrentRoute: getCurrentRoute,
     getQueryParameters: getQueryParameters,
     lastRouteChangeWasPopstate: lastRouteChangeWasPopstate,
     navigateTo: navigateTo,
     navigateToPreviousRoute: navigateToPreviousRoute,
   };
 });