Show notification instead of opening app launcher after extension installation

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': {
     # There are two sections of sources:
     # * "Platform"-based sources (OS, toolkit, etc.)
     # * Feature/directory-based sources (e.g., history, printing)
 
@@ skipping 675 matching lines @@
     # directory.
     'chrome_browser_ui_chromeos_sources': [
       'browser/ui/app_list/search/launcher_search/launcher_search_icon_image_loader.cc',
       'browser/ui/app_list/search/launcher_search/launcher_search_icon_image_loader.h',
       'browser/ui/app_list/search/launcher_search/launcher_search_icon_image_loader_impl.cc',
       'browser/ui/app_list/search/launcher_search/launcher_search_icon_image_loader_impl.h',
       'browser/ui/app_list/search/launcher_search/launcher_search_provider.cc',
       'browser/ui/app_list/search/launcher_search/launcher_search_provider.h',
       'browser/ui/app_list/search/launcher_search/launcher_search_result.cc',
       'browser/ui/app_list/search/launcher_search/launcher_search_result.h',
+      'browser/ui/extensions/extension_installed_notification.cc',
+      'browser/ui/extensions/extension_installed_notification.h',
       'browser/ui/input_method/input_method_engine_base.cc',
       'browser/ui/input_method/input_method_engine_base.h',
       'browser/ui/views/apps/chrome_native_app_window_views_aura_ash.cc',
       'browser/ui/views/apps/chrome_native_app_window_views_aura_ash.h',
       # On chromeos, file manager extension handles the file open/save dialog.
       'browser/ui/views/select_file_dialog_extension.cc',
       'browser/ui/views/select_file_dialog_extension.h',
       'browser/ui/views/select_file_dialog_extension_factory.cc',
       'browser/ui/views/select_file_dialog_extension_factory.h',
     ],
@@ skipping 2603 matching lines @@
           ],
           'sources': [
             '<@(chrome_browser_ui_non_mobile_sources)',
             '<@(chrome_browser_ui_omnibox_non_mobile_sources)',
           ],
         }],
       ],
     },
   ],
 }