Add a callback that notifies the QuicTransportClientSession visitor when the session is ready.

Also add a bit of extra defense in depth for ALPN checks.

gfe-relnote: n/a (not used in production)
PiperOrigin-RevId: 284658419
Change-Id: Ic665263a024821e529c564e7c8b86d362f9991a8
diff --git a/quic/quic_transport/quic_transport_client_session_test.cc b/quic/quic_transport/quic_transport_client_session_test.cc
index 51a0eb8..1225352 100644
--- a/quic/quic_transport/quic_transport_client_session_test.cc
+++ b/quic/quic_transport/quic_transport_client_session_test.cc
@@ -103,6 +103,7 @@
       "\0\x01"                    // length
       "/";                        // value
 
+  EXPECT_CALL(visitor_, OnSessionReady());
   Connect();
   EXPECT_TRUE(session_->IsSessionReady());