Fix bug introduced in https://codereview.chromium.org/679103004/,

net/base/net_log_logger.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 "net/base/net_log_logger.h"
 
 #include <stdio.h>
 
 #include "base/json/json_writer.h"
 #include "base/logging.h"
@@ skipping 44 matching lines @@
   std::string json;
   base::JSONWriter::Write(value.get(), &json);
   fprintf(file_.get(), "%s%s",
           (added_events_ ? ",\n" : ""),
           json.c_str());
   added_events_ = true;
 }
 
 // static
 base::DictionaryValue* NetLogLogger::GetConstants() {
-  return GetNetConstants().get();
+  return GetNetConstants().release();
 }
 
 }  // namespace net