Convert NULL to nullptr

minidump/minidump_thread_writer.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 37 matching lines @@
   //! This method is expected to be called by a MinidumpThreadListWriter in
   //! order to obtain a MINIDUMP_THREAD to include in its list.
   //!
   //! \note Valid in #kStateWritable.
   const MINIDUMP_THREAD* MinidumpThread() const;
 
   //! \brief Returns a MinidumpMemoryWriter that will write the memory region
   //!     corresponding to this object’s stack.
   //!
   //! If the thread does not have a stack, or its stack could not be determined,
-  //! this will return NULL.
+  //! this will return nullptr.
   //!
   //! This method is provided so that MinidumpThreadListWriter can obtain thread
   //! stack memory regions for the purposes of adding them to a
   //! MinidumpMemoryListWriter (configured by calling
   //! MinidumpThreadListWriter::SetMemoryListWriter()) by calling
   //! MinidumpMemoryListWriter::AddExtraMemory().
   //!
   //! \note Valid in any state.
   MinidumpMemoryWriter* Stack() const { return stack_; }
 
@@ skipping 107 matching lines @@
   MINIDUMP_THREAD_LIST thread_list_base_;
   std::vector<MinidumpThreadWriter*> threads_;  // weak
   MinidumpMemoryListWriter* memory_list_writer_;  // weak
 
   DISALLOW_COPY_AND_ASSIGN(MinidumpThreadListWriter);
 };
 
 }  // namespace crashpad
 
 #endif  // CRASHPAD_MINIDUMP_MINIDUMP_THREAD_WRITER_H_