gfe-relnote: In QUIC, only check whether framer has corresponding encrypter (before sending an ACK) when multiple packet number space is supported.

PiperOrigin-RevId: 245244813
Change-Id: I7b674a920b41726dfce25911f1a3e0f95b8a7067

quic/core/quic_connection.cc

diff --git a/quic/core/quic_connection.cc b/quic/core/quic_connection.cc
index ad56a06..417b22f 100644
--- a/quic/core/quic_connection.cc
+++ b/quic/core/quic_connection.cc
@@ -1514,7 +1514,8 @@
       // then a second packet is received; as that could cause the ACK for the
       // second packet to be delayed instead of immediate. This is currently
       // considered to be small enough of an edge case to not be optimized for.
-      if (framer_.HasEncrypterOfEncryptionLevel(QuicUtils::GetEncryptionLevel(
+      if (!SupportsMultiplePacketNumberSpaces() ||
+          framer_.HasEncrypterOfEncryptionLevel(QuicUtils::GetEncryptionLevel(
               QuicUtils::GetPacketNumberSpace(last_decrypted_packet_level_)))) {
         uber_received_packet_manager_.MaybeUpdateAckTimeout(
             should_last_packet_instigate_acks_, last_decrypted_packet_level_,