Make message center always scroll up upon notification removal

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 39 matching lines @@
         'message_center.cc',
         'message_center.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_style.cc',
         'message_center_style.h',
+        'message_center_switches.cc',
+        'message_center_switches.h',
         'message_center_tray.cc',
         'message_center_tray.h',
         'message_center_tray_delegate.h',
         'message_center_types.h',
         'notification.cc',
         'notification.h',
         'notification_blocker.cc',
         'notification_blocker.h',
         'notification_list.cc',
         'notification_list.h',
@@ skipping 175 matching lines @@
         # See http://crbug.com/162998#c4 for why this is needed.
         ['OS=="linux" and use_allocator!="none"', {
           'dependencies': [
             '../../base/allocator/allocator.gyp:allocator',
           ],
         }],
       ],
     },  # target_name: message_center_unittests
   ],
 }