Remove support for the keygen tag

chrome/test/data/policy/policy_test_cases.json

 {
   "-- Template --": {
     "intro": "Top-level entries map a policy name to its test parameters, described below. The name of the top level entry should be of the form <policy name>[.suffix]. The optional suffix is used for defining multiple test cases for a single policy.",
 
     "os": ["List of operating systems that support this policy. Valid values:", "win", "linux", "mac", "chromeos", "android", "Defaults to empty if not specified."],
     "official_only": "Whether this policy exists in official builds only. Defaults to |false| if not specified.",
     "can_be_recommended": "Whether a recommended value may be set for the policy. Defaults to |false| if not specified.",
     "test_policy": "A policy dictionary that should make the preferences affected by this policy become policy-controlled. Usually just sets the current policy. Defaults to an empty dictionary if not specified.",
     "note": "If the policy affects any preferences, the following array should be specified with one entry per such preference.",
     "pref_mappings": [
@@ skipping 1077 matching lines @@
           { "policy": { "DefaultJavaScriptSetting": 2 },
             "value": "block"}
         ]
       }
     ],
 
     "note": "TODO(bartfab): Flag this with can_be_recommended when http://crbug.com/106682 is fixed."
   },
 
   "DefaultKeygenSetting": {
-    "os": ["win", "linux", "mac", "chromeos", "android"],
-    "test_policy": { "DefaultKeygenSetting": 2 },
-    "pref_mappings": [
-      { "pref": "profile.managed_default_content_settings.keygen",
-        "indicator_selector": "[content-setting=keygen]",
-        "indicator_tests": [
-          { "policy": { "DefaultKeygenSetting": 1 },
-            "value": "allow"},
-          { "policy": { "DefaultKeygenSetting": 2 },
-            "value": "block"}
-        ]
-      }
-    ],
-
-    "note": "TODO(bartfab): Flag this with can_be_recommended when http://crbug.com/106682 is fixed."
+    "note": "This policy is retired, see https://crbug.com/568184."
   },
 
   "DefaultPluginsSetting": {
     "os": ["win", "linux", "mac", "chromeos"],
     "test_policy": { "DefaultPluginsSetting": 2 },
     "pref_mappings": [
       { "pref": "profile.managed_default_content_settings.plugins",
         "indicator_selector": "[content-setting=plugins]",
         "indicator_tests": [
           { "policy": { "DefaultPluginsSetting": 1 },
@@ skipping 315 matching lines @@
         "indicator_tests": [
           { "policy": { "JavaScriptBlockedForUrls": ["[*.]google.com"] } }
         ]
       }
     ],
 
     "note": "TODO(bartfab): Flag this with can_be_recommended when http://crbug.com/106682 is fixed."
   },
 
   "KeygenAllowedForUrls": {
-    "os": ["win", "linux", "mac", "chromeos", "android"],
-    "test_policy": { "KeygenAllowedForUrls": ["[*.]google.com"] },
-    "pref_mappings": [
-      { "pref": "profile.managed_keygen_allowed_for_urls",
-        "indicator_test_setup_js": "document.querySelector('button.exceptions-list-button[contentType=keygen]').click();",
-        "indicator_selector": "[content-exception=keygen]",
-        "indicator_tests": [
-          { "policy": { "KeygenAllowedForUrls": ["[*.]google.com"] } }
-        ]
-      }
-    ],
-
-    "note": "TODO(bartfab): Flag this with can_be_recommended when http://crbug.com/106682 is fixed."
+    "note": "This policy is retired, see https://crbug.com/568184."
   },
 
   "KeygenBlockedForUrls": {
-    "os": ["win", "linux", "mac", "chromeos", "android"],
-    "test_policy": { "KeygenBlockedForUrls": ["[*.]google.com"] },
-    "pref_mappings": [
-      { "pref": "profile.managed_keygen_blocked_for_urls",
-        "indicator_test_setup_js": "document.querySelector('button.exceptions-list-button[contentType=keygen]').click();",
-        "indicator_selector": "[content-exception=keygen]",
-        "indicator_tests": [
-          { "policy": { "KeygenBlockedForUrls": ["[*.]google.com"] } }
-        ]
-      }
-    ],
-
-    "note": "TODO(bartfab): Flag this with can_be_recommended when http://crbug.com/106682 is fixed."
+    "note": "This policy is retired, see https://crbug.com/568184."
   },
 
   "PluginsAllowedForUrls": {
     "os": ["win", "linux", "mac", "chromeos"],
     "test_policy": { "PluginsAllowedForUrls": ["[*.]google.com"] },
     "pref_mappings": [
       { "pref": "profile.managed_plugins_allowed_for_urls",
         "indicator_test_setup_js": "document.querySelector('button.exceptions-list-button[contentType=plugins]').click();",
         "indicator_selector": "[content-exception=plugins]",
         "indicator_tests": [
@@ skipping 1568 matching lines @@
 
   "AdditionalLaunchParameters": {
   },
 
   "SuppressChromeFrameTurndownPrompt": {
   },
 
   "SkipMetadataCheck": {
   }
 }