Gtk: Change NULL to nullptr

chrome/browser/ui/libgtkui/select_file_dialog_impl.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.
 //
 // This file implements common select dialog functionality between GTK and KDE.
 
 #include "chrome/browser/ui/libgtkui/select_file_dialog_impl.h"
 
 #include "base/environment.h"
 #include "base/files/file_util.h"
@@ skipping 10 matching lines @@
   NO_KDE,
   YES_KDE
 };
 
 UseKdeFileDialogStatus use_kde_ = UNKNOWN;
 
 }  // namespace
 
 namespace libgtkui {
 
-base::FilePath* SelectFileDialogImpl::last_saved_path_ = NULL;
-base::FilePath* SelectFileDialogImpl::last_opened_path_ = NULL;
+base::FilePath* SelectFileDialogImpl::last_saved_path_ = nullptr;
+base::FilePath* SelectFileDialogImpl::last_opened_path_ = nullptr;
 
 // static
 ui::SelectFileDialog* SelectFileDialogImpl::Create(
     ui::SelectFileDialog::Listener* listener,
     ui::SelectFilePolicy* policy) {
   DCHECK_CURRENTLY_ON(BrowserThread::UI);
   if (use_kde_ == UNKNOWN) {
     // Start out assumimg we are not going to use KDE.
     use_kde_ = NO_KDE;
 
@@ skipping 31 matching lines @@
       type_(SELECT_NONE) {
   if (!last_saved_path_) {
     last_saved_path_ = new base::FilePath();
     last_opened_path_ = new base::FilePath();
   }
 }
 
 SelectFileDialogImpl::~SelectFileDialogImpl() { }
 
 void SelectFileDialogImpl::ListenerDestroyed() {
-  listener_ = NULL;
+  listener_ = nullptr;
 }
 
 bool SelectFileDialogImpl::CallDirectoryExistsOnUIThread(
     const base::FilePath& path) {
   base::ThreadRestrictions::ScopedAllowIO allow_io;
   return base::DirectoryExists(path);
 }
 
 }  // namespace libgtkui