Move NotificationDelegate into message_center.

ui/message_center/message_center.gyp

 # 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.
 
 {
   'variables': {
     'chromium_code': 1,
   },
   'targets': [
     {
@@ skipping 24 matching lines @@
         'cocoa/tray_controller.h',
         'cocoa/tray_controller.mm',
         'cocoa/tray_view_controller.h',
         'cocoa/tray_view_controller.mm',
         'dummy_message_center.cc',
         'message_center.cc',
         'message_center.h',
         'message_center_constants.cc',
         'message_center_constants.h',
         'message_center_export.h',
+        'notification_delegate.cc',
+        'notification_delegate.h',
         'message_center_impl.cc',
         'message_center_impl.h',
         'message_center_observer.h',
         'message_center_switches.cc',
         'message_center_switches.h',
         'message_center_tray.cc',
         'message_center_tray.h',
         'message_center_tray_delegate.h',
         'message_center_util.cc',
         'message_center_util.h',
@@ skipping 114 matching lines @@
           'sources/': [
             # Exclude everything except main().
             ['exclude', '\\.(cc|mm)$'],
             ['include', '^test/run_all_unittests\\.cc$'],
           ],
         }],
       ],
     },  # target_name: message_center_unittests
   ],
 }