message: Avoid null deref in LOG
  Summary: data can be nullptr on end-of-stream?
diff: @@ -69,7 +69,9 @@ class EchoHandler : public quic::QuicSocket::ConnectionCallback,
  auto dataLen = (data ? data->computeChainDataLength() : 0);
  LOG(INFO) << "Got len=" << dataLen << " eof=" << uint32_t(eof)
  << " total=" << input_[id].first.chainLength() + dataLen
  - << " data=" << data->clone()->moveToFbString().toStdString();
  + << " data="
  + << ((data) ? data->clone()->moveToFbString().toStdString()
  + : std::string());
  input_[id].first.append(std::move(data));
  input_[id].second = eof;
  if (eof) {
  