Notificaitons refactor step 2

ui/message_center/notification_types.cc

 // 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.
 
-#include "ui/notifications/notification_types.h"
+#include "ui/message_center/notification_types.h"
 
-namespace ui {
-
-namespace notifications {
+namespace message_center {
 
 const char kMessageIntentKey[] = "message_intent";
 const char kPriorityKey[] = "priority";
 const char kTimestampKey[] = "timestamp";
 const char kUnreadCountKey[] = "unread_count";
 const char kButtonOneTitleKey[] = "button_one_title";
 const char kButtonOneIconUrlKey[] = "button_one_icon_url";
 const char kButtonTwoTitleKey[] = "button_two_title";
 const char kButtonTwoIconUrlKey[] = "button_two_icon_url";
 const char kExpandedMessageKey[] = "expanded_message";
 const char kImageUrlKey[] = "image_url";
 const char kItemsKey[] = "items";
 const char kItemTitleKey[] = "title";
 const char kItemMessageKey[] = "message";
 
-}  // namespace notifications
-
-}  // namespace ui
+}  // namespace message_center