Make MessageCenter a singleton object and build on Windows.

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.
 
 {
   'targets': [
     {
       'target_name': 'browser_ui',
       'type': 'static_library',
       'variables': { 'enable_wexit_time_destructors': 1, },
@@ skipping 2319 matching lines @@
             'browser/ui/gtk/gconf_titlebar_listener.h',
           ],
         }],
         ['use_ash==1', {
           'dependencies': [
             '../ash/ash.gyp:ash',
             '../ash/ash_strings.gyp:ash_strings',
             '../ui/message_center/message_center.gyp:message_center',
           ],
         }],
+        ['OS=="win"', {
+          'dependencies': [
+            '../ui/message_center/message_center.gyp:message_center'
+          ],
+        }],
         ['use_aura==1 and use_ash==0 and OS=="linux"', {
           'dependencies': [
             # gtk2 is the only component that can interact with gtk2 in our new
             # world.
             'browser/ui/libgtk2ui/libgtk2ui.gyp:gtk2ui',
           ],
         }],
         ['use_aura==1', {
           'sources/': [
             ['exclude', '^browser/ui/panels/display_settings_provider_win.cc'],
@@ skipping 443 matching lines @@
         }, { # else: enable_app_list==0
           'sources/': [
             ['exclude', '^browser/ui/views/app_list/'],
             ['exclude', '^browser/ui/app_list/'],
           ]
         }],
       ],
     },
   ],
 }