Rewrite scoped_ptr<T>(NULL) to use the default ctor in net/.

net/test/embedded_test_server/embedded_test_server.cc

 // Copyright (c) 2012 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 "net/test/embedded_test_server/embedded_test_server.h"
 
 #include "base/bind.h"
 #include "base/files/file_path.h"
 #include "base/file_util.h"
 #include "base/path_service.h"
@@ skipping 25 matching lines @@
   std::string request_path(request.relative_url.substr(1));
 
   // Remove the query string if present.
   size_t query_pos = request_path.find('?');
   if (query_pos != std::string::npos)
     request_path = request_path.substr(0, query_pos);
 
   std::string file_contents;
   if (!file_util::ReadFileToString(
           server_root.AppendASCII(request_path), &file_contents)) {
-    return scoped_ptr<HttpResponse>(NULL);
+    return scoped_ptr<HttpResponse>();
   }
 
   scoped_ptr<BasicHttpResponse> http_response(new BasicHttpResponse);
   http_response->set_code(net::test_server::SUCCESS);
   http_response->set_content(file_contents);
   return http_response.PassAs<HttpResponse>();
 }
 
 }  // namespace
 
@@ skipping 181 matching lines @@
   std::map<StreamListenSocket*, HttpConnection*>::iterator it =
       connections_.find(socket);
   if (it == connections_.end()) {
     return NULL;
   }
   return it->second;
 }
 
 }  // namespace test_server
 }  // namespace net