Rewrite scoped_ptr<T>(NULL) to use the default ctor in chrome/.

chrome/browser/ui/gtk/notifications/balloon_view_gtk.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 "chrome/browser/ui/gtk/notifications/balloon_view_gtk.h"
 
 #include <gtk/gtk.h>
 
 #include <string>
 #include <vector>
@@ skipping 86 matching lines @@
 }  // namespace
 
 BalloonViewImpl::BalloonViewImpl(BalloonCollection* collection)
     : balloon_(NULL),
       theme_service_(NULL),
       frame_container_(NULL),
       shelf_(NULL),
       hbox_(NULL),
       html_container_(NULL),
       weak_factory_(this),
-      close_button_(NULL),
-      animation_(NULL),
       menu_showing_(false),
-      pending_close_(false) {
-}
+      pending_close_(false) {}
 
 BalloonViewImpl::~BalloonViewImpl() {
   if (frame_container_) {
     GtkWidget* widget = frame_container_;
     frame_container_ = NULL;
     gtk_widget_hide(widget);
   }
 }
 
 void BalloonViewImpl::Close(bool by_user) {
@@ skipping 350 matching lines @@
         base::Bind(
             &BalloonViewImpl::DelayedClose, weak_factory_.GetWeakPtr(), false));
   }
 }
 
 gboolean BalloonViewImpl::OnDestroy(GtkWidget* widget) {
   frame_container_ = NULL;
   Close(false);
   return FALSE;  // Propagate.
 }