gfe-relnote: (n/a) In QuicClientBase, mark version negotiated when the client reconnects. Test only.

This is an attempt to deflake test SimpleRequestResponseZeroConnectionID and ZeroConnectionID.

PiperOrigin-RevId: 293356478
Change-Id: I63bbed4fde7a9fe71a1100660c7c82750c0bf74f
diff --git a/quic/core/quic_connection.h b/quic/core/quic_connection.h
index 56d88a3..b932164 100644
--- a/quic/core/quic_connection.h
+++ b/quic/core/quic_connection.h
@@ -484,6 +484,15 @@
     return framer_.supported_versions();
   }
 
+  // Mark version negotiated for this connection. Once called, the connection
+  // will ignore received version negotiation packets.
+  void SetVersionNegotiated() {
+    version_negotiated_ = true;
+    if (perspective_ == Perspective::IS_SERVER) {
+      framer_.InferPacketHeaderTypeFromVersion();
+    }
+  }
+
   // From QuicFramerVisitorInterface
   void OnError(QuicFramer* framer) override;
   bool OnProtocolVersionMismatch(ParsedQuicVersion received_version) override;