Add code count for quic_fix_http3_goaway_stream_id.

Protected by FLAGS_quic_reloadable_flag_quic_fix_http3_goaway_stream_id.

PiperOrigin-RevId: 334189975
Change-Id: I8c19fa14613f389b6bb603a08038de5d409006b7

quic/core/http/quic_spdy_session.cc

diff --git a/quic/core/http/quic_spdy_session.cc b/quic/core/http/quic_spdy_session.cc
index 7065c3b..1a6ecb0 100644
--- a/quic/core/http/quic_spdy_session.cc
+++ b/quic/core/http/quic_spdy_session.cc
@@ -722,6 +722,7 @@
       GetLargestPeerCreatedStreamId(/*unidirectional = */ false);
 
   if (GetQuicReloadableFlag(quic_fix_http3_goaway_stream_id)) {
+    QUIC_RELOADABLE_FLAG_COUNT(quic_fix_http3_goaway_stream_id);
     if (stream_id == QuicUtils::GetInvalidStreamId(transport_version())) {
       // No client-initiated bidirectional streams received yet.
       // Send 0 to let client know that all requests can be retried.