NULL -> nullptr under athena/

athena/activity/public/activity.h

 // 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.
 
 #ifndef ATHENA_ACTIVITY_PUBLIC_ACTIVITY_H_
 #define ATHENA_ACTIVITY_PUBLIC_ACTIVITY_H_
 
 #include <string>
 
 #include "athena/athena_export.h"
@@ skipping 76 matching lines @@
   // Returns the current media state.
   virtual ActivityMediaState GetMediaState() = 0;
 
   // Returns the window for the activity. This can be used to determine the
   // stacking order of this activity against others.
   // TODO(oshima): Consider returning base::Window window instead,
   // which has Show/ShowInactive and other control methods.
   virtual aura::Window* GetWindow() = 0;
 
   // Returns the web contents used to draw the content of the activity.
-  // This may return NULL if the web content is not available.
+  // This may return nullptr if the web content is not available.
   virtual content::WebContents* GetWebContents() = 0;
 
  protected:
   virtual ~Activity() {}
 };
 
 }  // namespace athena
 
 #endif  // ATHENA_ACTIVITY_PUBLIC_ACTIVITY_H_