Remove support for the keygen tag

components/content_settings/core/browser/content_settings_default_provider.cc

 // Copyright (c) 2012 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.
 
 #include "components/content_settings/core/browser/content_settings_default_provider.h"
 
 #include <string>
 #include <vector>
 
 #include "base/auto_reset.h"
@@ skipping 159 matching lines @@
       "ContentSettings.DefaultMediaStreamCameraSetting",
       IntToContentSetting(prefs_->GetInteger(
           GetPrefName(CONTENT_SETTINGS_TYPE_MEDIASTREAM_CAMERA))),
       CONTENT_SETTING_NUM_SETTINGS);
   UMA_HISTOGRAM_ENUMERATION(
       "ContentSettings.DefaultMIDISysExSetting",
       IntToContentSetting(prefs_->GetInteger(
           GetPrefName(CONTENT_SETTINGS_TYPE_MIDI_SYSEX))),
       CONTENT_SETTING_NUM_SETTINGS);
   UMA_HISTOGRAM_ENUMERATION(
-      "ContentSettings.DefaultKeygenSetting",
-      IntToContentSetting(prefs_->GetInteger(
-          GetPrefName(CONTENT_SETTINGS_TYPE_KEYGEN))),
-      CONTENT_SETTING_NUM_SETTINGS);
-  UMA_HISTOGRAM_ENUMERATION(
       "ContentSettings.DefaultWebBluetoothGuardSetting",
       IntToContentSetting(prefs_->GetInteger(
           GetPrefName(CONTENT_SETTINGS_TYPE_BLUETOOTH_GUARD))),
       CONTENT_SETTING_NUM_SETTINGS);
   UMA_HISTOGRAM_ENUMERATION(
       "ContentSettings.DefaultAutoplaySetting",
       IntToContentSetting(prefs_->GetInteger(
           GetPrefName(CONTENT_SETTINGS_TYPE_AUTOPLAY))),
       CONTENT_SETTING_NUM_SETTINGS);
 #endif
@@ skipping 177 matching lines @@
   // deleted.
 #if !defined(OS_IOS)
   prefs_->ClearPref(kObsoleteFullscreenDefaultPref);
 #if !defined(OS_ANDROID)
   prefs_->ClearPref(kObsoleteMouseLockDefaultPref);
 #endif  // !defined(OS_ANDROID)
 #endif  // !defined(OS_IOS)
 }
 
 }  // namespace content_settings