chrome.settingsPrivate: Implement onPrefsChanged event handling.

chrome/chrome_browser_extensions.gypi

 # Copyright (c) 2013 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_extensions_chromeos_sources': [
       'browser/extensions/api/enterprise_platform_keys/enterprise_platform_keys_api.cc',
       'browser/extensions/api/enterprise_platform_keys/enterprise_platform_keys_api.h',
       'browser/extensions/api/enterprise_platform_keys_private/enterprise_platform_keys_private_api.cc',
@@ skipping 376 matching lines @@
       'browser/extensions/api/runtime/chrome_runtime_api_delegate.cc',
       'browser/extensions/api/runtime/chrome_runtime_api_delegate.h',
       'browser/extensions/api/screenlock_private/screenlock_private_api.cc',
       'browser/extensions/api/screenlock_private/screenlock_private_api.h',
       'browser/extensions/api/sessions/session_id.cc',
       'browser/extensions/api/sessions/session_id.h',
       'browser/extensions/api/sessions/sessions_api.cc',
       'browser/extensions/api/sessions/sessions_api.h',
       'browser/extensions/api/settings_overrides/settings_overrides_api.cc',
       'browser/extensions/api/settings_overrides/settings_overrides_api.h',
+      'browser/extensions/api/settings_private/prefs_util.cc',
+      'browser/extensions/api/settings_private/prefs_util.h',
       'browser/extensions/api/settings_private/settings_private_api.cc',
       'browser/extensions/api/settings_private/settings_private_api.h',
       'browser/extensions/api/settings_private/settings_private_delegate.cc',
       'browser/extensions/api/settings_private/settings_private_delegate.h',
       'browser/extensions/api/settings_private/settings_private_delegate_factory.cc',
       'browser/extensions/api/settings_private/settings_private_delegate_factory.h',
+      'browser/extensions/api/settings_private/settings_private_event_router.cc',
+      'browser/extensions/api/settings_private/settings_private_event_router.h',
+      'browser/extensions/api/settings_private/settings_private_event_router_factory.cc',
+      'browser/extensions/api/settings_private/settings_private_event_router_factory.h',
       'browser/extensions/api/signed_in_devices/id_mapping_helper.cc',
       'browser/extensions/api/signed_in_devices/id_mapping_helper.h',
       'browser/extensions/api/signed_in_devices/signed_in_devices_api.cc',
       'browser/extensions/api/signed_in_devices/signed_in_devices_api.h',
       'browser/extensions/api/signed_in_devices/signed_in_devices_manager.cc',
       'browser/extensions/api/signed_in_devices/signed_in_devices_manager.h',
       'browser/extensions/api/spellcheck/spellcheck_api.cc',
       'browser/extensions/api/spellcheck/spellcheck_api.h',
       'browser/extensions/api/storage/setting_sync_data.cc',
       'browser/extensions/api/storage/setting_sync_data.h',
@@ skipping 644 matching lines @@
           ],
         }, {  # use_brlapi==0
           'sources': [
             'browser/extensions/api/braille_display_private/braille_controller_stub.cc',
           ],
         }],
       ],
     },
   ],
 }