tree 4b95e435cc53d44cf835322c190c2ae693fa12b5
parent b541621d2faf9f610feb77f64c462acba96b16cc
author QUICHE team <quiche-dev@google.com> 1750185129 -0700
committer Copybara-Service <copybara-worker@google.com> 1750185185 -0700

This PR adds the support to probe alternative path on RTO instead of receiving a new connection ID. If RTO triggers while the client is not actively validating a path, it will probe for the multipath on RTO.

```
- The PR adds the connection option "MPR1".
- Probe for alternative path on RTO.
- Add kMPR1 option to enable probing on RTO.
- Add unit test and e2e test.
```

Protected by QUIC connection option for multiport.

PiperOrigin-RevId: 772554253