Integrate About page into Settings for Chrome OS settings in a window.

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.
 
 {
   'variables': {
     'chrome_browser_ui_non_ios_sources': [
       'browser/ui/accelerator_utils.h',
       'browser/ui/android/android_about_app_info.cc',
       'browser/ui/android/android_about_app_info.h',
@@ skipping 1695 matching lines @@
       'browser/ui/webui/options/create_profile_handler.cc',
       'browser/ui/webui/options/create_profile_handler.h',
       'browser/ui/webui/options/font_settings_handler.cc',
       'browser/ui/webui/options/font_settings_handler.h',
       'browser/ui/webui/options/font_settings_utils.h',
       'browser/ui/webui/options/font_settings_utils_linux.cc',
       'browser/ui/webui/options/font_settings_utils_mac.mm',
       'browser/ui/webui/options/font_settings_utils_win.cc',
       'browser/ui/webui/options/handler_options_handler.cc',
       'browser/ui/webui/options/handler_options_handler.h',
+      'browser/ui/webui/options/help_overlay_handler.cc',
+      'browser/ui/webui/options/help_overlay_handler.h',
       'browser/ui/webui/options/home_page_overlay_handler.cc',
       'browser/ui/webui/options/home_page_overlay_handler.h',
       'browser/ui/webui/options/import_data_handler.cc',
       'browser/ui/webui/options/import_data_handler.h',
       'browser/ui/webui/options/language_dictionary_overlay_handler.cc',
       'browser/ui/webui/options/language_dictionary_overlay_handler.h',
       'browser/ui/webui/options/language_options_handler.cc',
       'browser/ui/webui/options/language_options_handler.h',
       'browser/ui/webui/options/language_options_handler_common.cc',
       'browser/ui/webui/options/language_options_handler_common.h',
@@ skipping 1232 matching lines @@
         }],
         ['OS!="android" and OS!="ios"', {
           'dependencies': [
             '../device/bluetooth/bluetooth.gyp:device_bluetooth',
           ],
         }],
       ],
     },
   ],
 }