short circuit QUIC packets to packet buffer if there is already a CHLO on same connection buffered …

net/quic/core/quic_flags_list.h

Index: net/quic/core/quic_flags_list.h
diff --git a/net/quic/core/quic_flags_list.h b/net/quic/core/quic_flags_list.h
index 36c20555045c441d695abf5b913b515d05f5b2ea..660fedd8aa80c8ccb377f463d8fff78c418e0e65 100644
--- a/net/quic/core/quic_flags_list.h
+++ b/net/quic/core/quic_flags_list.h
@@ -154,3 +154,7 @@ QUIC_FLAG(bool, FLAGS_quic_release_crypto_stream_buffer, false)
 // Use a more conservative backoff of 2x instead of 1.5x for handshake
 // retransmissions, as well as a larger minimum.
 QUIC_FLAG(bool, FLAGS_quic_conservative_handshake_retransmits, true)
+
+// If true, buffer packets while parsing public headers instead of parsing down
+// if CHLO is already buffered.
+QUIC_FLAG(bool, FLAGS_quic_buffer_packets_after_chlo, false);