Remove support for the keygen tag

chrome/browser/content_settings/tab_specific_content_settings.h

 // 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.
 
 #ifndef CHROME_BROWSER_CONTENT_SETTINGS_TAB_SPECIFIC_CONTENT_SETTINGS_H_
 #define CHROME_BROWSER_CONTENT_SETTINGS_TAB_SPECIFIC_CONTENT_SETTINGS_H_
 
 #include <stdint.h>
 
 #include <map>
@@ skipping 339 matching lines @@
                               bool blocked_by_policy);
   void OnServiceWorkerAccessed(const GURL& scope,
                                bool blocked_by_policy_javascript,
                                bool blocked_by_policy_cookie);
   void OnWebDatabaseAccessed(const GURL& url,
                              const base::string16& name,
                              const base::string16& display_name,
                              bool blocked_by_policy);
   void OnGeolocationPermissionSet(const GURL& requesting_frame,
                                   bool allowed);
-  void OnDidUseKeygen(const GURL& url);
 #if defined(OS_ANDROID) || defined(OS_CHROMEOS)
   void OnProtectedMediaIdentifierPermissionSet(const GURL& requesting_frame,
                                                bool allowed);
 #endif
 
   // This method is called to update the status about the microphone and
   // camera stream access.
   void OnMediaStreamPermissionSet(
       const GURL& request_origin,
       MicrophoneCameraState new_microphone_camera_state,
@@ skipping 119 matching lines @@
   // Holds the previous committed url during a navigation.
   GURL previous_url_;
 
   // Observer to watch for content settings changed.
   ScopedObserver<HostContentSettingsMap, content_settings::Observer> observer_;
 
   DISALLOW_COPY_AND_ASSIGN(TabSpecificContentSettings);
 };
 
 #endif  // CHROME_BROWSER_CONTENT_SETTINGS_TAB_SPECIFIC_CONTENT_SETTINGS_H_