std::string RenderThreadImpl::GetLocale() {
  const CommandLine& parsed_command_line = *CommandLine::ForCurrentProcess();
  const std::string& lang =
      parsed_command_line.GetSwitchValueASCII(switches::kLang);
  DCHECK(!lang.empty());
  return lang;
}

The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.