Remove support for the keygen tag

chrome/test/data/webui/settings/site_details_tests.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 Suite of tests for site-details. */
 cr.define('site_details', function() {
   function registerTests() {
     suite('SiteDetails', function() {
       /**
        * A site list element created before each test.
@@ skipping 47 matching lines @@
             },
           ],
           javascript: [
             {
               embeddingOrigin: 'https://foo-allow.com:443',
               origin: 'https://foo-allow.com:443',
               setting: 'allow',
               source: 'preference',
             },
           ],
-          keygen: [
-            {
-              embeddingOrigin: 'https://foo-allow.com:443',
-              origin: 'https://foo-allow.com:443',
-              setting: 'allow',
-              source: 'preference',
-            },
-          ],
           mic: [
             {
               embeddingOrigin: 'https://foo-allow.com:443',
               origin: 'https://foo-allow.com:443',
               setting: 'allow',
               source: 'preference',
             },
           ],
           notifications: [
             {
@@ skipping 123 matching lines @@
 
         //expect usage to be rendered
         assertTrue(!!testElement.$$('#usage'));
       });
     });
   }
   return {
     registerTests: registerTests,
   };
 });