Deprecate quic_dispatcher_legacy_version_encapsulation

Deprecate gfe2_reloadable_flag_quic_dispatcher_legacy_version_encapsulation

PiperOrigin-RevId: 328359439
Change-Id: I79de4e1e5e8bac5f41bd10acc5a8451481c9d686

quic/core/http/end_to_end_test.cc

diff --git a/quic/core/http/end_to_end_test.cc b/quic/core/http/end_to_end_test.cc
index cfb7671..25df532 100644
--- a/quic/core/http/end_to_end_test.cc
+++ b/quic/core/http/end_to_end_test.cc
@@ -4726,7 +4726,6 @@
     ASSERT_TRUE(Initialize());
     return;
   }
-  SetQuicReloadableFlag(quic_dispatcher_legacy_version_encapsulation, true);
   client_config_.SetClientConnectionOptions(QuicTagVector{kQLVE});
   ASSERT_TRUE(Initialize());
   SendSynchronousFooRequestAndCheckResponse();
@@ -4750,7 +4749,6 @@
     ASSERT_TRUE(Initialize());
     return;
   }
-  SetQuicReloadableFlag(quic_dispatcher_legacy_version_encapsulation, true);
   client_config_.SetClientConnectionOptions(QuicTagVector{kQLVE});
   constexpr auto kCustomParameter =
       static_cast<TransportParameters::TransportParameterId>(0xff34);
@@ -4774,7 +4772,6 @@
   }
   client_supported_versions_.insert(client_supported_versions_.begin(),
                                     QuicVersionReservedForNegotiation());
-  SetQuicReloadableFlag(quic_dispatcher_legacy_version_encapsulation, true);
   client_config_.SetClientConnectionOptions(QuicTagVector{kQLVE});
   ASSERT_TRUE(Initialize());
   SendSynchronousFooRequestAndCheckResponse();
@@ -4793,7 +4790,6 @@
     return;
   }
   SetPacketLossPercentage(30);
-  SetQuicReloadableFlag(quic_dispatcher_legacy_version_encapsulation, true);
   client_config_.SetClientConnectionOptions(QuicTagVector{kQLVE});
   // Disable blackhole detection as this test is testing loss recovery.
   client_extra_copts_.push_back(kNBHD);

quic/core/quic_dispatcher.cc

diff --git a/quic/core/quic_dispatcher.cc b/quic/core/quic_dispatcher.cc
index 7275adf..972a9ac 100644
--- a/quic/core/quic_dispatcher.cc
+++ b/quic/core/quic_dispatcher.cc
@@ -194,14 +194,10 @@
     if (chlo.GetStringPiece(kALPN, &alpn_value)) {
       alpn_ = std::string(alpn_value);
     }
-    if (GetQuicReloadableFlag(quic_dispatcher_legacy_version_encapsulation)) {
-      QUIC_RELOADABLE_FLAG_COUNT_N(quic_dispatcher_legacy_version_encapsulation,
-                                   1, 3);
-      if (version == LegacyVersionForEncapsulation().transport_version) {
-        quiche::QuicheStringPiece qlve_value;
-        if (chlo.GetStringPiece(kQLVE, &qlve_value)) {
-          legacy_version_encapsulation_inner_packet_ = std::string(qlve_value);
-        }
+    if (version == LegacyVersionForEncapsulation().transport_version) {
+      quiche::QuicheStringPiece qlve_value;
+      if (chlo.GetStringPiece(kQLVE, &qlve_value)) {
+        legacy_version_encapsulation_inner_packet_ = std::string(qlve_value);
       }
     }
   }
@@ -209,7 +205,6 @@
   std::string&& ConsumeAlpn() { return std::move(alpn_); }
 
   std::string&& ConsumeLegacyVersionEncapsulationInnerPacket() {
-    DCHECK(GetQuicReloadableFlag(quic_dispatcher_legacy_version_encapsulation));
     return std::move(legacy_version_encapsulation_inner_packet_);
   }
 
@@ -222,7 +217,6 @@
     QuicDispatcher* dispatcher,
     ChloAlpnExtractor* alpn_extractor,
     const ReceivedPacketInfo& packet_info) {
-  DCHECK(GetQuicReloadableFlag(quic_dispatcher_legacy_version_encapsulation));
   std::string legacy_version_encapsulation_inner_packet =
       alpn_extractor->ConsumeLegacyVersionEncapsulationInnerPacket();
   if (legacy_version_encapsulation_inner_packet.empty()) {
@@ -489,23 +483,19 @@
   auto it = session_map_.find(server_connection_id);
   if (it != session_map_.end()) {
     DCHECK(!buffered_packets_.HasBufferedPackets(server_connection_id));
-    if (GetQuicReloadableFlag(quic_dispatcher_legacy_version_encapsulation)) {
-      QUIC_RELOADABLE_FLAG_COUNT_N(quic_dispatcher_legacy_version_encapsulation,
-                                   2, 3);
-      if (packet_info.version_flag &&
-          packet_info.version != it->second->version() &&
-          packet_info.version == LegacyVersionForEncapsulation()) {
-        // This packet is using the Legacy Version Encapsulation version but the
-        // corresponding session isn't, attempt extraction of inner packet.
-        ChloAlpnExtractor alpn_extractor;
-        if (ChloExtractor::Extract(packet_info.packet, packet_info.version,
-                                   config_->create_session_tag_indicators(),
-                                   &alpn_extractor,
-                                   server_connection_id.length())) {
-          if (MaybeHandleLegacyVersionEncapsulation(this, &alpn_extractor,
-                                                    packet_info)) {
-            return true;
-          }
+    if (packet_info.version_flag &&
+        packet_info.version != it->second->version() &&
+        packet_info.version == LegacyVersionForEncapsulation()) {
+      // This packet is using the Legacy Version Encapsulation version but the
+      // corresponding session isn't, attempt extraction of inner packet.
+      ChloAlpnExtractor alpn_extractor;
+      if (ChloExtractor::Extract(packet_info.packet, packet_info.version,
+                                 config_->create_session_tag_indicators(),
+                                 &alpn_extractor,
+                                 server_connection_id.length())) {
+        if (MaybeHandleLegacyVersionEncapsulation(this, &alpn_extractor,
+                                                  packet_info)) {
+          return true;
         }
       }
     }
@@ -676,14 +666,11 @@
         break;
       }
 
-      if (GetQuicReloadableFlag(quic_dispatcher_legacy_version_encapsulation)) {
-        QUIC_RELOADABLE_FLAG_COUNT_N(
-            quic_dispatcher_legacy_version_encapsulation, 3, 3);
-        if (MaybeHandleLegacyVersionEncapsulation(this, &alpn_extractor,
-                                                  *packet_info)) {
-          break;
-        }
+      if (MaybeHandleLegacyVersionEncapsulation(this, &alpn_extractor,
+                                                *packet_info)) {
+        break;
       }
+
       ProcessChlo({alpn_extractor.ConsumeAlpn()}, packet_info);
     } break;
     case kFateTimeWait:

quic/core/quic_dispatcher_test.cc

diff --git a/quic/core/quic_dispatcher_test.cc b/quic/core/quic_dispatcher_test.cc
index 1fa601f..e90489a 100644
--- a/quic/core/quic_dispatcher_test.cc
+++ b/quic/core/quic_dispatcher_test.cc
@@ -587,7 +587,6 @@
     // is not currently supported in QuicDispatcher.
     return;
   }
-  SetQuicReloadableFlag(quic_dispatcher_legacy_version_encapsulation, true);
   QuicSocketAddress client_address(QuicIpAddress::Loopback4(), 1);
   QuicConnectionId server_connection_id = TestConnectionId();
   QuicConfig client_config = DefaultQuicConfig();