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

extensions/browser/content_verifier_io_data.cc

 // 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.
 
 #include "extensions/browser/content_verifier_io_data.h"
 
 #include "content/public/browser/browser_thread.h"
 
 namespace extensions {
 
@@ skipping 33 matching lines @@
 }
 
 const ContentVerifierIOData::ExtensionData* ContentVerifierIOData::GetData(
     const std::string& extension_id) {
   DCHECK_CURRENTLY_ON(content::BrowserThread::IO);
   std::map<std::string, linked_ptr<ExtensionData> >::iterator found =
       data_map_.find(extension_id);
   if (found != data_map_.end())
     return found->second.get();
   else
-    return NULL;
+    return nullptr;
 }
 
 }  // namespace extensions