Remove support for the keygen tag

chrome/browser/resources/settings/site_settings/site_settings_behavior.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.
 
 /**
  * @fileoverview Behavior common to Site Settings classes.
  */
 
 /** @polymerBehavior */
 var SiteSettingsBehaviorImpl = {
@@ skipping 101 matching lines @@
         return loadTimeData.getString('siteSettingsFlashAskBefore');
       case settings.ContentSettingsTypes.BACKGROUND_SYNC:
         // "Allow sites to finish sending and receiving data" vs "Do not allow".
         if (!categoryEnabled) {
           return loadTimeData.getString('siteSettingsBackgroundSyncBlocked');
         }
         return showRecommendation ?
             loadTimeData.getString(
                  'siteSettingsAllowRecentlyClosedSitesRecommended') :
             loadTimeData.getString('siteSettingsAllowRecentlyClosedSites');
-      case settings.ContentSettingsTypes.KEYGEN:
-        // "Allow sites to use keygen" vs "Do not allow".
-        if (categoryEnabled) {
-          return loadTimeData.getString('siteSettingsKeygenAllow');
-        }
-        return showRecommendation ?
-            loadTimeData.getString('siteSettingsKeygenBlockRecommended') :
-            loadTimeData.getString('siteSettingsKeygenBlock');
       case settings.ContentSettingsTypes.AUTOMATIC_DOWNLOADS:
         // "Ask when a site wants to auto-download multiple" vs "Do not allow".
         if (!categoryEnabled) {
           return loadTimeData.getString('siteSettingsAutoDownloadBlock');
         }
         return showRecommendation ?
             loadTimeData.getString('siteSettingsAutoDownloadAskRecommended') :
             loadTimeData.getString('siteSettingsAutoDownloadAsk');
       case settings.ContentSettingsTypes.UNSANDBOXED_PLUGINS:
         // "Ask when a plugin accesses your computer" vs "Do not allow".
@@ skipping 164 matching lines @@
       incognito: exception.incognito,
       setting: exception.setting,
       source: exception.source,
     };
   },
 
 };
 
 /** @polymerBehavior */
 var SiteSettingsBehavior = [SiteSettingsBehaviorImpl];