Add http3_constants.h for HTTP/3 and QPACK unidirectional stream types and settings identifiers.
In the future, HTTP/3-specific constants from quic/core/*.h can be moved here,
and HTTP/3 and QPACK-specific error codes might also live here.
Also update unused kSettingsNumPlaceholders value from 8 to 9 according to
https://quicwg.org/base-drafts/draft-ietf-quic-http.html#settings-parameters.
Also add unused QPACK settings identifiers.
gfe-relnote: n/a, QUIC v99-only change.
PiperOrigin-RevId: 258613141
Change-Id: I48cf9d6468ae99018dbe49b74c9740b8e48a287d
diff --git a/quic/core/http/quic_spdy_session.cc b/quic/core/http/quic_spdy_session.cc
index 4a8dad7..8bbe7a4 100644
--- a/quic/core/http/quic_spdy_session.cc
+++ b/quic/core/http/quic_spdy_session.cc
@@ -9,6 +9,7 @@
#include <string>
#include <utility>
+#include "net/third_party/quiche/src/quic/core/http/http_constants.h"
#include "net/third_party/quiche/src/quic/core/http/quic_headers_stream.h"
#include "net/third_party/quiche/src/quic/core/quic_utils.h"
#include "net/third_party/quiche/src/quic/platform/api/quic_bug_tracker.h"
