Deprecate quic_enable_h3_datagrams

This CL deprecates gfe2_reloadable_flag_quic_enable_h3_datagrams.

PiperOrigin-RevId: 595161542

quiche/quic/core/http/quic_spdy_session.cc

diff --git a/quiche/quic/core/http/quic_spdy_session.cc b/quiche/quic/core/http/quic_spdy_session.cc
index 941a874..9a937c7 100644
--- a/quiche/quic/core/http/quic_spdy_session.cc
+++ b/quiche/quic/core/http/quic_spdy_session.cc
@@ -489,9 +489,7 @@
       destruction_indicator_(123456789),
       allow_extended_connect_(perspective() == Perspective::IS_SERVER &&
                               VersionUsesHttp3(transport_version())),
-      force_buffer_requests_until_settings_(false),
-      quic_enable_h3_datagrams_flag_(
-          GetQuicReloadableFlag(quic_enable_h3_datagrams)) {
+      force_buffer_requests_until_settings_(false) {
   h2_deframer_.set_visitor(spdy_framer_visitor_.get());
   h2_deframer_.set_debug_visitor(spdy_framer_visitor_.get());
   spdy_framer_.set_debug_visitor(spdy_framer_visitor_.get());
@@ -553,7 +551,6 @@
         settings_.values[SETTINGS_H3_DATAGRAM_DRAFT04] = 1;
         break;
       case HttpDatagramSupport::kRfc:
-        QUIC_RELOADABLE_FLAG_COUNT(quic_enable_h3_datagrams);
         settings_.values[SETTINGS_H3_DATAGRAM] = 1;
         break;
       case HttpDatagramSupport::kRfcAndDraft04:
@@ -1906,10 +1903,7 @@
 }
 
 HttpDatagramSupport QuicSpdySession::LocalHttpDatagramSupport() {
-  if (quic_enable_h3_datagrams_flag_) {
-    return HttpDatagramSupport::kRfc;
-  }
-  return HttpDatagramSupport::kNone;
+  return HttpDatagramSupport::kRfc;
 }
 
 std::string HttpDatagramSupportToString(

quiche/quic/core/http/quic_spdy_session.h

diff --git a/quiche/quic/core/http/quic_spdy_session.h b/quiche/quic/core/http/quic_spdy_session.h
index bf6d82b..4c01b18 100644
--- a/quiche/quic/core/http/quic_spdy_session.h
+++ b/quiche/quic/core/http/quic_spdy_session.h
@@ -708,9 +708,6 @@
   // Allows forcing ShouldBufferRequestsUntilSettings() to true via
   // a connection option.
   bool force_buffer_requests_until_settings_;
-
-  // Latched value of quic_enable_h3_datagrams reloadable flag.
-  bool quic_enable_h3_datagrams_flag_;
 };
 
 }  // namespace quic

quiche/quic/core/quic_flags_list.h

diff --git a/quiche/quic/core/quic_flags_list.h b/quiche/quic/core/quic_flags_list.h
index 8808af3..0d9f9a4 100644
--- a/quiche/quic/core/quic_flags_list.h
+++ b/quiche/quic/core/quic_flags_list.h
@@ -117,8 +117,6 @@
 QUIC_FLAG(quic_reloadable_flag_quic_bbr2_simplify_inflight_hi, true)
 // When true, the BBR4 copt sets the extra_acked window to 20 RTTs and BBR5 sets it to 40 RTTs.
 QUIC_FLAG(quic_reloadable_flag_quic_bbr2_extra_acked_window, true)
-// When true, we will send HTTP/3 setting 0x33 to indicate that we support RFC 9297.
-QUIC_FLAG(quic_reloadable_flag_quic_enable_h3_datagrams, true)
 
 #endif