Run clang-modernize -use-nullptr over src/extensions/.

extensions/browser/extension_registry.cc

 // Copyright 2013 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 "extensions/browser/extension_registry.h"
 
 #include "base/strings/string_util.h"
 #include "extensions/browser/extension_registry_factory.h"
 #include "extensions/browser/extension_registry_observer.h"
 
@@ skipping 90 matching lines @@
   if (include_mask & TERMINATED) {
     const Extension* extension = terminated_extensions_.GetByID(lowercase_id);
     if (extension)
       return extension;
   }
   if (include_mask & BLACKLISTED) {
     const Extension* extension = blacklisted_extensions_.GetByID(lowercase_id);
     if (extension)
       return extension;
   }
-  return NULL;
+  return nullptr;
 }
 
 bool ExtensionRegistry::AddEnabled(
     const scoped_refptr<const Extension>& extension) {
   return enabled_extensions_.Insert(extension);
 }
 
 bool ExtensionRegistry::RemoveEnabled(const std::string& id) {
   return enabled_extensions_.Remove(id);
 }
@@ skipping 37 matching lines @@
   disabled_extensions_.set_modification_callback(callback);
 }
 
 void ExtensionRegistry::Shutdown() {
   // Release references to all Extension objects in the sets.
   ClearAll();
   FOR_EACH_OBSERVER(ExtensionRegistryObserver, observers_, OnShutdown(this));
 }
 
 }  // namespace extensions