Convert NULL to nullptr

util/mac/mac_util.cc

 // 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 81 matching lines @@
 
   return darwin_major_version;
 }
 
 // Helpers for the weak-imported private CoreFoundation internals.
 
 CFDictionaryRef TryCFCopySystemVersionDictionary() {
   if (_CFCopySystemVersionDictionary) {
     return _CFCopySystemVersionDictionary();
   }
-  return NULL;
+  return nullptr;
 }
 
 CFDictionaryRef TryCFCopyServerVersionDictionary() {
   if (_CFCopyServerVersionDictionary) {
     return _CFCopyServerVersionDictionary();
   }
-  return NULL;
+  return nullptr;
 }
 
 const void* TryCFDictionaryGetValue(CFDictionaryRef dictionary,
                                     const void* value) {
   if (value) {
     return CFDictionaryGetValue(dictionary, value);
   }
-  return NULL;
+  return nullptr;
 }
 
 // Converts |version| to a triplet of version numbers on behalf of
 // MacOSXVersion(). Returns true on success. If |version| does not have the
 // expected format, returns false. |version| must be in the form "10.9.2" or
 // just "10.9". In the latter case, |bugfix| will be set to 0.
 bool StringToVersionNumbers(const std::string& version,
                             int* major,
                             int* minor,
                             int* bugfix) {
@@ skipping 145 matching lines @@
         IORegistryEntryDataPropertyAsString(platform_expert, CFSTR("model")));
     board_id->assign(IORegistryEntryDataPropertyAsString(platform_expert,
                                                          CFSTR("board-id")));
   } else {
     model->clear();
     board_id->clear();
   }
 }
 
 }  // namespace crashpad