gfe-relnote: In QUIC, populate nonretransmittable_frames in SerializedPacket. Protected by gfe2_reloadable_flag_quic_populate_nonretransmittable_frames.

PiperOrigin-RevId: 275833395
Change-Id: I96d8663e89354a777cabb9e636eede9e61002d26
diff --git a/quic/core/quic_packets.h b/quic/core/quic_packets.h
index 82647c6..fcb2e56 100644
--- a/quic/core/quic_packets.h
+++ b/quic/core/quic_packets.h
@@ -370,6 +370,7 @@
   const char* encrypted_buffer;
   QuicPacketLength encrypted_length;
   QuicFrames retransmittable_frames;
+  QuicFrames nonretransmittable_frames;
   IsHandshake has_crypto_handshake;
   // -1: full padding to the end of a max-sized packet
   //  0: no padding