NULL -> nullptr under athena/

athena/content/app_activity_proxy.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/app_activity_proxy.h"
 
 #include "athena/content/app_activity.h"
 #include "athena/content/app_activity_registry.h"
 #include "athena/wm/public/window_list_provider.h"
 #include "athena/wm/public/window_manager.h"
@@ skipping 42 matching lines @@
 Activity::ActivityMediaState AppActivityProxy::GetMediaState() {
   // This proxy has never any media playing.
   return ACTIVITY_MEDIA_STATE_NONE;
 }
 
 aura::Window* AppActivityProxy::GetWindow() {
   return view_->GetWidget()->GetNativeWindow();
 }
 
 content::WebContents* AppActivityProxy::GetWebContents() {
-  return NULL;
+  return nullptr;
 }
 
 void AppActivityProxy::Init() {
   DCHECK(replaced_activity_);
   // Get the content proxy to present the content.
   content_proxy_ = replaced_activity_->GetContentProxy();
   WindowListProvider* window_list_provider =
       WindowManager::Get()->GetWindowListProvider();
   window_list_provider->StackWindowBehindTo(GetWindow(),
                                             replaced_activity_->GetWindow());
   // After the Init() function returns, the passed |replaced_activity_| might
   // get destroyed. Since we do not need it anymore we reset it.
-  replaced_activity_ = NULL;
+  replaced_activity_ = nullptr;
 }
 
 SkColor AppActivityProxy::GetRepresentativeColor() const {
   return color_;
 }
 
 base::string16 AppActivityProxy::GetTitle() const {
   return title_;
 }
 
 gfx::ImageSkia AppActivityProxy::GetIcon() const {
   return gfx::ImageSkia();
 }
 
 bool AppActivityProxy::UsesFrame() const {
   return true;
 }
 
 views::View* AppActivityProxy::GetContentsView() {
   return view_;
 }
 
 views::Widget* AppActivityProxy::CreateWidget() {
-  return NULL;
+  return nullptr;
 }
 
 gfx::ImageSkia AppActivityProxy::GetOverviewModeImage() {
   return content_proxy_->GetContentImage();
 }
 
 void AppActivityProxy::PrepareContentsForOverview() {
 }
 
 void AppActivityProxy::ResetContentsView() {
 }
 
 }  // namespace athena