gfe-relnote: In QUIC, fix a misuse of largest_packet_peer_knows_is_acked when multiple packet number space is enabled. This is protected by existing FLAG_quic_supports_tls_handshake.

PiperOrigin-RevId: 257666510
Change-Id: I9174a4c3576810fcd39e468a28f8f19b93f86a3a

quic/core/quic_connection.cc

diff --git a/quic/core/quic_connection.cc b/quic/core/quic_connection.cc
index 7f3f01e..099217a 100644
--- a/quic/core/quic_connection.cc
+++ b/quic/core/quic_connection.cc
@@ -3383,7 +3383,10 @@
   if (no_stop_waiting_frames_) {
     uber_received_packet_manager_.DontWaitForPacketsBefore(
         last_decrypted_packet_level_,
-        sent_packet_manager_.largest_packet_peer_knows_is_acked());
+        SupportsMultiplePacketNumberSpaces()
+            ? sent_packet_manager_.GetLargestPacketPeerKnowsIsAcked(
+                  last_decrypted_packet_level_)
+            : sent_packet_manager_.largest_packet_peer_knows_is_acked());
   }
   // Always reset the retransmission alarm when an ack comes in, since we now
   // have a better estimate of the current rtt than when it was set.

quic/core/quic_sent_packet_manager.h

diff --git a/quic/core/quic_sent_packet_manager.h b/quic/core/quic_sent_packet_manager.h
index cc462b1..944c556 100644
--- a/quic/core/quic_sent_packet_manager.h
+++ b/quic/core/quic_sent_packet_manager.h
@@ -339,6 +339,7 @@
   }
 
   QuicPacketNumber largest_packet_peer_knows_is_acked() const {
+    DCHECK(!supports_multiple_packet_number_spaces());
     return largest_packet_peer_knows_is_acked_;
   }