Notificaitons refactor step 2

ui/message_center/message_center_bubble.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/message_center/message_center_bubble.h"
 
 #include "grit/ui_strings.h"
 #include "third_party/skia/include/core/SkPaint.h"
 #include "ui/base/l10n/l10n_util.h"
 #include "ui/base/resource/resource_bundle.h"
@@ skipping 490 matching lines @@
   contents_view_->FocusContents();
 }
 
 void MessageCenterBubble::OnBubbleViewDestroyed() {
   contents_view_ = NULL;
 }
 
 void MessageCenterBubble::UpdateBubbleView() {
   if (!bubble_view())
     return;  // Could get called after view is closed
-  NotificationList::Notifications notifications;
-  list_delegate()->GetNotificationList()->GetNotifications(&notifications);
+  const NotificationList::Notifications& notifications =
+      list_delegate()->GetNotificationList()->GetNotifications();
   contents_view_->Update(notifications);
   bubble_view()->Show();
   bubble_view()->UpdateBubble();
 }
 
 void MessageCenterBubble::OnMouseEnteredView() {
 }
 
 void MessageCenterBubble::OnMouseExitedView() {
 }
 
 size_t MessageCenterBubble::NumMessageViewsForTest() const {
   return contents_view_->NumMessageViews();
 }
 
 }  // namespace message_center