Implement systemInfo.storage.onChanged event

chrome/chrome_browser_extensions.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_extensions',
       'type': 'static_library',
       'variables': { 'enable_wexit_time_destructors': 1, },
@@ skipping 618 matching lines @@
         'browser/extensions/shell_window_geometry_cache.cc',
         'browser/extensions/shell_window_geometry_cache.h',
         'browser/extensions/shell_window_registry.cc',
         'browser/extensions/shell_window_registry.h',
         'browser/extensions/standard_management_policy_provider.cc',
         'browser/extensions/standard_management_policy_provider.h',
         'browser/extensions/startup_helper.cc',
         'browser/extensions/startup_helper.h',
         'browser/extensions/state_store.cc',
         'browser/extensions/state_store.h',
+        'browser/extensions/storage_info_observer.h',
         'browser/extensions/system/system_api.cc',
         'browser/extensions/system/system_api.h',
         'browser/extensions/system_info_provider.h',
         'browser/extensions/system_info_event_router.cc',
         'browser/extensions/system_info_event_router.h',
         'browser/extensions/tab_helper.cc',
         'browser/extensions/tab_helper.h',
         'browser/extensions/theme_installed_infobar_delegate.cc',
         'browser/extensions/theme_installed_infobar_delegate.h',
         'browser/extensions/unpacked_installer.cc',
@@ skipping 260 matching lines @@
           'msvs_settings': {
             'VCLinkerTool': {
               'SubSystem': '2',  # Set /SUBSYSTEM:WINDOWS
             },
           },
         },
       ],
     }, ],  # 'OS=="win"'
   ],  # 'conditions'
 }