Add SessionStateObserver with ActiveUserChanged()

chrome/chrome_browser_ui.gypi

 # Copyright 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.
 
 {
   'targets': [
     {
       'target_name': 'browser_ui',
       'type': 'static_library',
       'variables': { 'enable_wexit_time_destructors': 1, },
@@ skipping 231 matching lines @@
         'browser/ui/ash/launcher/launcher_item_controller.cc',
         'browser/ui/ash/launcher/launcher_item_controller.h',
         'browser/ui/ash/launcher/launcher_application_menu_item_model.cc',
         'browser/ui/ash/launcher/launcher_application_menu_item_model.h',
         'browser/ui/ash/launcher/shell_window_launcher_item_controller.cc',
         'browser/ui/ash/launcher/shell_window_launcher_item_controller.h',
         'browser/ui/ash/launcher/shell_window_launcher_controller.cc',
         'browser/ui/ash/launcher/shell_window_launcher_controller.h',
         'browser/ui/ash/screenshot_taker.cc',
         'browser/ui/ash/screenshot_taker.h',
-        'browser/ui/ash/session_state_delegate.h',
         'browser/ui/ash/session_state_delegate_chromeos.cc',
+        'browser/ui/ash/session_state_delegate_chromeos.h',
         'browser/ui/ash/session_state_delegate_views.cc',
+        'browser/ui/ash/session_state_delegate_views.h',
         'browser/ui/ash/tabs/dock_info_ash.cc',
         'browser/ui/ash/tabs/dock_info_ash.h',
         'browser/ui/ash/tabs/dock_info_chromeos.cc',
         'browser/ui/ash/user_action_handler.cc',
         'browser/ui/ash/user_action_handler.h',
         'browser/ui/ash/user_wallpaper_delegate_win.cc',
         'browser/ui/ash/user_wallpaper_delegate_win.h',
         'browser/ui/ash/volume_controller_chromeos.cc',
         'browser/ui/ash/volume_controller_chromeos.h',
         'browser/ui/ash/window_positioner.cc',
@@ skipping 2707 matching lines @@
             ['exclude', '^browser/ui/views/app_list/'],
             ['exclude', '^browser/ui/app_list/'],
             ['include', '^browser/ui/app_list/app_list_service.h'],
             ['include', '^browser/ui/app_list/app_list_service_disabled.cc'],
           ],
         }],
       ],
     },
   ],
 }