Silence unused variable warning on Windows

brightray/browser/url_request_context_getter.cc

@@ -154,6 +154,7 @@ net::URLRequestContext* URLRequestContextGetter::GetURLRequestContext() {
         end = protocol_handlers_.end(); it != end; ++it) {
       bool set_protocol = job_factory->SetProtocolHandler(
           it->first, it->second.release());
+      ALLOW_UNUSED(set_protocol);
       DCHECK(set_protocol);
     }
     protocol_handlers_.clear();