void ResourceDispatcherHostImpl::OnSyncLoad(
    int request_id,
    const ResourceHostMsg_Request& request_data,
    IPC::Message* sync_result) {
  BeginRequest(request_id, request_data, sync_result,
                sync_result->routing_id());
 }

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.