status_icons: Factor out status icon observer into its own header file.

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',
@@ skipping 2045 matching lines @@
         'browser/ssl/ssl_blocking_page.h',
         'browser/ssl/ssl_client_auth_observer.cc',
         'browser/ssl/ssl_client_auth_observer.h',
         'browser/ssl/ssl_error_info.cc',
         'browser/ssl/ssl_error_info.h',
         'browser/ssl_client_certificate_selector.h',
         'browser/status_icons/desktop_notification_balloon.cc',
         'browser/status_icons/desktop_notification_balloon.h',
         'browser/status_icons/status_icon.cc',
         'browser/status_icons/status_icon.h',
+        'browser/status_icons/status_icon_observer.h',
         'browser/status_icons/status_tray.cc',
         'browser/status_icons/status_tray.h',
         'browser/sync/glue/app_notification_data_type_controller.cc',
         'browser/sync/glue/app_notification_data_type_controller.h',
         'browser/sync/glue/autofill_data_type_controller.cc',
         'browser/sync/glue/autofill_data_type_controller.h',
         'browser/sync/glue/autofill_profile_data_type_controller.cc',
         'browser/sync/glue/autofill_profile_data_type_controller.h',
         'browser/sync/glue/backend_data_type_configurer.h',
         'browser/sync/glue/bookmark_change_processor.cc',
@@ skipping 3002 matching lines @@
         'browser/metrics/proto/study.proto',
       ],
       'variables': {
         'proto_in_dir': 'browser/metrics/proto',
         'proto_out_dir': 'chrome/browser/metrics/proto',
       },
       'includes': [ '../build/protoc.gypi' ]
     },
   ],
 }