Remove support for the keygen tag

chrome/test/data/chromeos/enterprise/policies

 { u'prod_enterprise_executive_user': {
     u'user_recommended_policies': {},
     u'user_mandatory_policies': {
       u'ExtensionInstallForcelist': [
         (u'kcnhkahnjcbndmmehfkdnkjomaanaooo;'
          'https://clients2.google.com/service/update2/crx'),
         (u'boidnimkebefpfgbeekbjoponilnomle;'
          'https://clients2.google.com/service/update2/crx'),
         (u'khgabmflimjjbclkmljlpmgaleanedem;'
          'https://clients2.google.com/service/update2/crx'),
         (u'inmnggcpelemfookhlhkdfbechcdadfp;'
          'https://clients2.google.com/service/update2/crx')],
       u'PolicyRefreshRate': 28800000,
       u'PrintingEnabled': True}},
 
   u'prod_enterprise_sales_user': {
     u'user_mandatory_policies': {
       u'AlternateErrorPagesEnabled': False,
       u'AutoFillEnabled': False,
       u'ChromeOsLockOnIdleSuspend': False,
       u'DefaultCookiesSetting': 2,
       u'DefaultGeolocationSetting': 2,
       u'DefaultImagesSetting': 2,
       u'DefaultJavaScriptSetting': 2,
-      u'DefaultKeygenSetting': 2,
       u'DefaultNotificationsSetting': 2,
       u'DefaultPluginsSetting': 2,
       u'DefaultPopupsSetting': 2,
       u'DefaultSearchProviderEnabled': True,
       u'DefaultSearchProviderEncodings': [u'UTF-8'],
       u'DefaultSearchProviderIconURL': u'http://www.engadget.icon',
       u'DefaultSearchProviderInstantURL': u'http://www.engadget.com/instant',
       u'DefaultSearchProviderKeyword': u'engadget.com',
       u'DefaultSearchProviderName': u'engadget',
       u'DefaultSearchProviderSearchURL':
@@ skipping 41 matching lines @@
       u'URLWhitelist': [u'https://google.com']}},
 
   u'prod_enterprise_development_user': {
     u'user_mandatory_policies': {
       u'AlternateErrorPagesEnabled': True,
       u'ChromeOsLockOnIdleSuspend': True,
       u'DefaultCookiesSetting': 1,
       u'DefaultGeolocationSetting': 3,
       u'DefaultImagesSetting': 1,
       u'DefaultJavaScriptSetting': 1,
-      u'DefaultKeygenSetting': 2,
       u'DefaultNotificationsSetting': 1,
       u'DefaultPluginsSetting': 1,
       u'DefaultPopupsSetting': 1,
       u'DefaultSearchProviderEnabled': True,
       u'DefaultSearchProviderEncodings': [
         u'"UTF-8"',
         u'"UTF-16"',
         u'"GB2312"',
         u'"ISO-8859-1"'],
       u'DefaultSearchProviderIconURL': u'',
@@ skipping 33 matching lines @@
       u'ProxyServer': u'cache.corp.google.com:3128',
       u'SearchSuggestEnabled': True,
       u'ShowHomeButton': True,
       u'SyncDisabled': False}},
 
   u'prod_enterprise_test_user': {
     u'user_mandatory_policies': {
       u'PolicyRefreshRate': 5400000,
       u'ProxyPacUrl': u'http://proxyconfig.corp.google.com/wpad.dat',
       u'DefaultJavaScriptSetting': 1,
-      u'DefaultKeygenSetting': 2,
       u'RestoreOnStartup': 4,
       u'DefaultSearchProviderSuggestURL':
         u'http://search.my.company/suggest?q={searchTerms}',
       u'ProxyMode': u'pac_script',
       u'DefaultGeolocationSetting': 1,
       u'DefaultCookiesSetting': 1,
       u'RestoreOnStartupURLs':
         [u'http://cnn.com',
          u'nytimes.com',
          u'msnbc.com',
@@ skipping 41 matching lines @@
       u'SyncDisabled': False,
       u'URLWhitelist': [u'https://google.com'],
       u'DefaultImagesSetting': 1, u'DefaultSearchProviderEnabled': True}},
 
   u'prod_enterprise_operations_user': {
     u'user_mandatory_policies': {
       u'ChromeOsLockOnIdleSuspend': True,
       u'DefaultCookiesSetting': 1,
       u'DefaultGeolocationSetting': 1,
       u'DefaultJavaScriptSetting': 1,
-      u'DefaultKeygenSetting': 2,
       u'DefaultNotificationsSetting': 1,
       u'DefaultPopupsSetting': 2,
       u'DefaultSearchProviderEnabled': True,
       u'DefaultSearchProviderEncodings': [
         u'UTF-8',
         u'UTF-16',
         u'GB2312',
         u'ISO-8859-1'],
       u'DefaultSearchProviderIconURL': u'',
       u'DefaultSearchProviderInstantURL': u'',
@@ skipping 56 matching lines @@
 
   u'test_enterprise_sales_user': {
     u'user_mandatory_policies': {
       u'AlternateErrorPagesEnabled': False,
       u'AutoFillEnabled': False,
       u'ChromeOsLockOnIdleSuspend': False,
       u'DefaultCookiesSetting': 2,
       u'DefaultGeolocationSetting': 2,
       u'DefaultImagesSetting': 2,
       u'DefaultJavaScriptSetting': 2,
-      u'DefaultKeygenSetting': 2,
       u'DefaultNotificationsSetting': 2,
       u'DefaultPluginsSetting': 2,
       u'DefaultPopupsSetting': 2,
       u'DefaultSearchProviderEnabled': True,
       u'DefaultSearchProviderEncodings': [u'UTF-8'],
       u'DefaultSearchProviderIconURL': u'http://www.engadget.icon',
       u'DefaultSearchProviderInstantURL': u'http://www.engadget.com/instant',
       u'DefaultSearchProviderKeyword': u'engadget.com',
       u'DefaultSearchProviderName': u'engadget',
       u'DefaultSearchProviderSearchURL':
@@ skipping 41 matching lines @@
       u'URLWhitelist': [u'https://google.com']}},
 
   u'test_enterprise_development_user': {
     u'user_mandatory_policies': {
       u'AlternateErrorPagesEnabled': True,
       u'ChromeOsLockOnIdleSuspend': True,
       u'DefaultCookiesSetting': 1,
       u'DefaultGeolocationSetting': 3,
       u'DefaultImagesSetting': 1,
       u'DefaultJavaScriptSetting': 1,
-      u'DefaultKeygenSetting': 2,
       u'DefaultNotificationsSetting': 1,
       u'DefaultPluginsSetting': 1,
       u'DefaultPopupsSetting': 1,
       u'DefaultSearchProviderEnabled': True,
       u'DefaultSearchProviderEncodings': [
         u'"UTF-8"',
         u'"UTF-16"',
         u'"GB2312"',
         u'"ISO-8859-1"'],
       u'DefaultSearchProviderIconURL': u'',
@@ skipping 33 matching lines @@
       u'ProxyServer': u'cache.corp.google.com:3128',
       u'SearchSuggestEnabled': True,
       u'ShowHomeButton': True,
       u'SyncDisabled': False}},
 
   u'test_enterprise_test_user': {
     u'user_mandatory_policies': {
       u'PolicyRefreshRate': 5400000,
       u'ProxyPacUrl': u'http://proxyconfig.corp.google.com/wpad.dat',
       u'DefaultJavaScriptSetting': 1,
-      u'DefaultKeygenSetting': 2,
       u'RestoreOnStartup': 4,
       u'DefaultSearchProviderSuggestURL':
         u'http://search.my.company/suggest?q={searchTerms}',
       u'ProxyMode': u'pac_script',
       u'DefaultGeolocationSetting': 1,
       u'DefaultCookiesSetting': 1,
       u'RestoreOnStartupURLs':
         [u'http://cnn.com',
          u'nytimes.com',
          u'msnbc.com',
@@ skipping 41 matching lines @@
       u'SyncDisabled': False,
       u'URLWhitelist': [u'https://google.com'],
       u'DefaultImagesSetting': 1, u'DefaultSearchProviderEnabled': True}},
 
   u'test_enterprise_operations_user': {
     u'user_mandatory_policies': {
       u'ChromeOsLockOnIdleSuspend': True,
       u'DefaultCookiesSetting': 1,
       u'DefaultGeolocationSetting': 1,
       u'DefaultJavaScriptSetting': 1,
-      u'DefaultKeygenSetting': 2,
       u'DefaultNotificationsSetting': 1,
       u'DefaultPopupsSetting': 2,
       u'DefaultSearchProviderEnabled': True,
       u'DefaultSearchProviderEncodings': [
         u'UTF-8',
         u'UTF-16',
         u'GB2312',
         u'ISO-8859-1'],
       u'DefaultSearchProviderIconURL': u'',
       u'DefaultSearchProviderInstantURL': u'',
@@ skipping 161 matching lines @@
         u'*@crosqa2.com',
         u'*@crosqa3.com'],
       u'ChromeOsReleaseChannelDelegated': True,
       u'DeviceDataRoamingEnabled': False,
       u'DeviceMetricsReportingEnabled': False,
       u'DeviceShowUserNamesOnSignin': False,
       u'ReportDeviceActivityTimes': False,
       u'ReportDeviceBootMode': False,
       u'ReportDeviceVersionInfo': False}},
 }