Support token based address validation in IETF QUIC.

Protected by FLAGS_quic_reloadable_flag_quic_enable_token_based_address_validation.

PiperOrigin-RevId: 346305075
Change-Id: I65c7ad821518b1c33c96018928cad03f010056f8
diff --git a/quic/core/quic_packet_creator.h b/quic/core/quic_packet_creator.h
index f1ace67..2605740 100644
--- a/quic/core/quic_packet_creator.h
+++ b/quic/core/quic_packet_creator.h
@@ -468,6 +468,9 @@
   // different from the current one, flush all the queue frames first.
   void SetDefaultPeerAddress(QuicSocketAddress address);
 
+  // Return true if retry_token_ is not empty.
+  bool HasRetryToken() const;
+
   bool let_connection_handle_pings() const {
     return let_connection_handle_pings_;
   }