Enable user change background image in settings page in Aura build.

chrome/chrome_browser.gypi

 # 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.
 
 {
   'targets': [
     {
       'target_name': 'browser',
       'type': 'static_library',
       'variables': { 'enable_wexit_time_destructors': 1, },
@@ skipping 743 matching lines @@
         'browser/chromeos/options/network_config_view.cc',
         'browser/chromeos/options/network_config_view.h',
         'browser/chromeos/options/passphrase_textfield.cc',
         'browser/chromeos/options/passphrase_textfield.h',
         'browser/chromeos/options/take_photo_dialog.cc',
         'browser/chromeos/options/take_photo_dialog.h',
         'browser/chromeos/options/vpn_config_view.cc',
         'browser/chromeos/options/vpn_config_view.h',
         'browser/chromeos/options/wifi_config_view.cc',
         'browser/chromeos/options/wifi_config_view.h',
+        'browser/chromeos/options2/desktop_background_observer.cc',
+        'browser/chromeos/options2/desktop_background_observer.h',
         'browser/chromeos/panels/panel_scroller.cc',
         'browser/chromeos/panels/panel_scroller.h',
         'browser/chromeos/panels/panel_scroller_container.cc',
         'browser/chromeos/panels/panel_scroller_container.h',
         'browser/chromeos/panels/panel_scroller_header.cc',
         'browser/chromeos/panels/panel_scroller_header.h',
         'browser/chromeos/power/brightness_observer.cc',
         'browser/chromeos/power/brightness_observer.h',
         'browser/chromeos/power/low_battery_observer.cc',
         'browser/chromeos/power/low_battery_observer.h',
@@ skipping 3410 matching lines @@
         'browser/ui/webui/options2/chromeos/language_mozc_handler2.cc',
         'browser/ui/webui/options2/chromeos/language_mozc_handler2.h',
         'browser/ui/webui/options2/chromeos/language_options_util2.cc',
         'browser/ui/webui/options2/chromeos/language_options_util2.h',
         'browser/ui/webui/options2/chromeos/language_pinyin_handler2.cc',
         'browser/ui/webui/options2/chromeos/language_pinyin_handler2.h',
         'browser/ui/webui/options2/chromeos/pointer_handler2.cc',
         'browser/ui/webui/options2/chromeos/pointer_handler2.h',
         'browser/ui/webui/options2/chromeos/proxy_handler2.cc',
         'browser/ui/webui/options2/chromeos/proxy_handler2.h',
+        'browser/ui/webui/options2/chromeos/set_wallpaper_options_handler2.cc',
+        'browser/ui/webui/options2/chromeos/set_wallpaper_options_handler2.h',
         'browser/ui/webui/options2/chromeos/stats_options_handler2.cc',
         'browser/ui/webui/options2/chromeos/stats_options_handler2.h',
         'browser/ui/webui/options2/chromeos/system_settings_provider2.cc',
         'browser/ui/webui/options2/chromeos/system_settings_provider2.h',
         'browser/ui/webui/options2/chromeos/user_image_source2.cc',
         'browser/ui/webui/options2/chromeos/user_image_source2.h',
         'browser/ui/webui/options2/chromeos/virtual_keyboard_manager_handler2.cc',
         'browser/ui/webui/options2/chromeos/virtual_keyboard_manager_handler2.h',
         'browser/ui/webui/options2/clear_browser_data_handler2.cc',
         'browser/ui/webui/options2/clear_browser_data_handler2.h',
@@ skipping 1451 matching lines @@
       'type': 'static_library',
       'sources': [ 'browser/history/in_memory_url_index_cache.proto' ],
       'variables': {
         'proto_in_dir': 'browser/history',
         'proto_out_dir': 'chrome/browser/history',
       },
       'includes': [ '../build/protoc.gypi' ]
     },
   ],
 }