tree f4df908d970924652f122bf777a15486bedad31c
parent 8777a794cd2b7bfd149883a2dcd551cd1d71a5e2
author QUICHE team <quiche-dev@google.com> 1557947121 -0700
committer Copybara-Service <copybara-worker@google.com> 1557968486 -0700

Change QuartcClientEndpoint to handle client-side version negotiation.

This allows Quartc to stop forcing the "no connection version negotiation" flags
to false, as QuartcEndpoint can now handle version negotiation properly in
either case.  (QuartcServerEndpoint already handles server-side version
negotiation through the QuartcDispatcher.)  In-connection version negotiation is
not fully reliable anyway, as some features of new QUIC versions cannot be
enabled or disabled in-place within a QuicConnection object (for example,
changes to how stream ids are allocated).

This only requires three changes:
 - QuartcEndpoint::Delegate extends QuartcSession::Delegate
 - QuartcClientEndpoint sits between the session and the final delegate
 - When QuartcClientEndpoint sees a QUIC_INVALID_VERSION error, it picks another
   version and tries again

This change is mostly cleanup to combine Endpoint and Session delegates and add
required overrides to existing delegates.

The only other minor change required is that QuartcMediaTransport must now
accept more than one call to OnSessionCreated().  All we have to do is remove
the DCHECK to allow this--nothing else assumes it will only happen once.

gfe-relnote: n/a (Quartc only)
PiperOrigin-RevId: 248378366
Change-Id: I442bd69e45f5d65e43d3e99118159f11dc595169