NULL -> nullptr under athena/

athena/content/app_registry_impl.cc

 // Copyright 2014 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 "athena/content/public/app_registry.h"
 
 #include "athena/content/app_activity_registry.h"
 #include "base/logging.h"
 
 namespace athena {
@@ skipping 13 matching lines @@
   virtual void RemoveAppActivityRegistry(
       AppActivityRegistry* registry) override;
 
   std::vector<AppActivityRegistry*> app_list_;
 
   DISALLOW_COPY_AND_ASSIGN(AppRegistryImpl);
 };
 
 namespace {
 
-AppRegistryImpl* instance = NULL;
+AppRegistryImpl* instance = nullptr;
 
 }  // namespace
 
 AppRegistryImpl::AppRegistryImpl() {
 }
 AppRegistryImpl::~AppRegistryImpl() {
   DCHECK(app_list_.empty());
 }
 
 AppActivityRegistry* AppRegistryImpl::GetAppActivityRegistry(
@@ skipping 36 matching lines @@
 
 // static
 void AppRegistry::ShutDown() {
   DCHECK(instance);
   delete instance;
 }
 
 AppRegistry::AppRegistry() {}
 
 AppRegistry::~AppRegistry() {
-  instance = NULL;
+  instance = nullptr;
 }
 
 }  // namespace athena