Convert NULL to nullptr

snapshot/process_snapshot.h

 // Copyright 2014 The Crashpad Authors. All rights reserved.
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
 // you may not use this file except in compliance with the License.
 // You may obtain a copy of the License at
 //
 //     http://www.apache.org/licenses/LICENSE-2.0
 //
 // Unless required by applicable law or agreed to in writing, software
 // distributed under the License is distributed on an "AS IS" BASIS,
@@ skipping 86 matching lines @@
   //!     ownership of these objects, they are scoped to the lifetime of the
   //!     ProcessSnapshot object that they were obtained from.
   virtual std::vector<const ThreadSnapshot*> Threads() const = 0;
 
   //! \brief Returns an ExceptionSnapshot reflecting the exception that the
   //!     snapshot process sustained to trigger the snapshot being taken.
   //!
   //! \return An ExceptionSnapshot object. The caller does not take ownership of
   //!     this object, it is scoped to the lifetime of the ProcessSnapshot
   //!     object that it was obtained from. If the snapshot is not a result of
-  //!     an exception, returns `NULL`.
+  //!     an exception, returns `nullptr`.
   virtual const ExceptionSnapshot* Exception() const = 0;
 
  protected:
   ~ProcessSnapshot() {}
 };
 
 }  // namespace crashpad
 
 #endif  // CRASHPAD_SNAPSHOT_PROCESS_SNAPSHOT_H_