gfe-relnote: deprecate gfe2_reloadable_flag_quic_enable_version_50

PiperOrigin-RevId: 284025291
Change-Id: I26591c4c77425a5d434a16d9a3456f217273240b
diff --git a/quic/core/quic_dispatcher_test.cc b/quic/core/quic_dispatcher_test.cc
index 896438a..0f78020 100644
--- a/quic/core/quic_dispatcher_test.cc
+++ b/quic/core/quic_dispatcher_test.cc
@@ -865,7 +865,6 @@
 
 TEST_F(QuicDispatcherTest, ProcessPacketWithInvalidShortInitialConnectionId) {
   // Enable a version that supports connection IDs of length different than 8.
-  SetQuicReloadableFlag(quic_enable_version_50, true);
   CreateTimeWaitListManager();
 
   QuicSocketAddress client_address(QuicIpAddress::Loopback4(), 1);
@@ -911,7 +910,6 @@
 TEST_F(QuicDispatcherTest, SupportedTransportVersionsChangeInFlight) {
   static_assert(QUIC_ARRAYSIZE(kSupportedTransportVersions) == 6u,
                 "Supported versions out of sync");
-  SetQuicReloadableFlag(quic_enable_version_50, true);
   SetQuicReloadableFlag(quic_enable_version_99, true);
 
   VerifyVersionNotSupported(QuicVersionReservedForNegotiation());
@@ -920,15 +918,15 @@
                                            QuicVersionMin().transport_version));
   VerifyVersionSupported(QuicVersionMax());
 
-  // Turn off version 50.
-  SetQuicReloadableFlag(quic_enable_version_50, false);
+  // Turn off version 99.
+  SetQuicReloadableFlag(quic_enable_version_99, false);
   VerifyVersionNotSupported(
-      ParsedQuicVersion(PROTOCOL_QUIC_CRYPTO, QUIC_VERSION_50));
+      ParsedQuicVersion(PROTOCOL_QUIC_CRYPTO, QUIC_VERSION_99));
 
-  // Turn on version 50.
-  SetQuicReloadableFlag(quic_enable_version_50, true);
+  // Turn on version 99.
+  SetQuicReloadableFlag(quic_enable_version_99, true);
   VerifyVersionSupported(
-      ParsedQuicVersion(PROTOCOL_QUIC_CRYPTO, QUIC_VERSION_50));
+      ParsedQuicVersion(PROTOCOL_QUIC_CRYPTO, QUIC_VERSION_99));
 }
 
 TEST_F(QuicDispatcherTest, RejectDeprecatedVersionsWithVersionNegotiation) {
diff --git a/quic/core/quic_version_manager.cc b/quic/core/quic_version_manager.cc
index 476bbc7..95cac21 100644
--- a/quic/core/quic_version_manager.cc
+++ b/quic/core/quic_version_manager.cc
@@ -16,7 +16,6 @@
 QuicVersionManager::QuicVersionManager(
     ParsedQuicVersionVector supported_versions)
     : enable_version_99_(GetQuicReloadableFlag(quic_enable_version_99)),
-      enable_version_50_(GetQuicReloadableFlag(quic_enable_version_50)),
       enable_tls_(GetQuicReloadableFlag(quic_supports_tls_handshake)),
       allowed_supported_versions_(std::move(supported_versions)) {
   static_assert(QUIC_ARRAYSIZE(kSupportedTransportVersions) == 6u,
@@ -41,10 +40,8 @@
   static_assert(QUIC_ARRAYSIZE(kSupportedTransportVersions) == 6u,
                 "Supported versions out of sync");
   if (enable_version_99_ != GetQuicReloadableFlag(quic_enable_version_99) ||
-      enable_version_50_ != GetQuicReloadableFlag(quic_enable_version_50) ||
       enable_tls_ != GetQuicReloadableFlag(quic_supports_tls_handshake)) {
     enable_version_99_ = GetQuicReloadableFlag(quic_enable_version_99);
-    enable_version_50_ = GetQuicReloadableFlag(quic_enable_version_50);
     enable_tls_ = GetQuicReloadableFlag(quic_supports_tls_handshake);
     RefilterSupportedVersions();
   }
diff --git a/quic/core/quic_version_manager.h b/quic/core/quic_version_manager.h
index 0851464..e66e01f 100644
--- a/quic/core/quic_version_manager.h
+++ b/quic/core/quic_version_manager.h
@@ -43,8 +43,6 @@
   // Cached value of reloadable flags.
   // quic_enable_version_99 flag
   bool enable_version_99_;
-  // quic_enable_version_50 flag
-  bool enable_version_50_;
   // quic_supports_tls_handshake flag
   bool enable_tls_;
 
diff --git a/quic/core/quic_version_manager_test.cc b/quic/core/quic_version_manager_test.cc
index 48623a8..19cf5bd 100644
--- a/quic/core/quic_version_manager_test.cc
+++ b/quic/core/quic_version_manager_test.cc
@@ -19,17 +19,11 @@
   static_assert(QUIC_ARRAYSIZE(kSupportedTransportVersions) == 6u,
                 "Supported versions out of sync");
   SetQuicReloadableFlag(quic_enable_version_99, false);
-  SetQuicReloadableFlag(quic_enable_version_50, false);
   QuicVersionManager manager(AllSupportedVersions());
 
   EXPECT_EQ(FilterSupportedTransportVersions(AllSupportedTransportVersions()),
             manager.GetSupportedTransportVersions());
 
-  EXPECT_EQ(QuicTransportVersionVector({QUIC_VERSION_49, QUIC_VERSION_48,
-                                        QUIC_VERSION_46, QUIC_VERSION_43}),
-            manager.GetSupportedTransportVersions());
-
-  SetQuicReloadableFlag(quic_enable_version_50, true);
   EXPECT_EQ(QuicTransportVersionVector({QUIC_VERSION_50, QUIC_VERSION_49,
                                         QUIC_VERSION_48, QUIC_VERSION_46,
                                         QUIC_VERSION_43}),
@@ -41,12 +35,6 @@
                                         QUIC_VERSION_46, QUIC_VERSION_43}),
             manager.GetSupportedTransportVersions());
 
-  SetQuicReloadableFlag(quic_enable_version_99, true);
-  EXPECT_EQ(QuicTransportVersionVector({QUIC_VERSION_99, QUIC_VERSION_50,
-                                        QUIC_VERSION_49, QUIC_VERSION_48,
-                                        QUIC_VERSION_46, QUIC_VERSION_43}),
-            manager.GetSupportedTransportVersions());
-
   // Ensure that all versions are now supported.
   EXPECT_EQ(FilterSupportedTransportVersions(AllSupportedTransportVersions()),
             manager.GetSupportedTransportVersions());
diff --git a/quic/core/quic_versions.cc b/quic/core/quic_versions.cc
index abeb64e..420a2a4 100644
--- a/quic/core/quic_versions.cc
+++ b/quic/core/quic_versions.cc
@@ -262,10 +262,6 @@
       if (GetQuicReloadableFlag(quic_enable_version_99)) {
         filtered_versions.push_back(version);
       }
-    } else if (version.transport_version == QUIC_VERSION_50) {
-      if (GetQuicReloadableFlag(quic_enable_version_50)) {
-        filtered_versions.push_back(version);
-      }
     } else {
       filtered_versions.push_back(version);
     }
@@ -467,9 +463,6 @@
   if (parsed_version.transport_version == QUIC_VERSION_99) {
     SetQuicReloadableFlag(quic_enable_version_99, true);
   }
-  if (parsed_version.transport_version == QUIC_VERSION_50) {
-    SetQuicReloadableFlag(quic_enable_version_50, true);
-  }
 }
 
 #undef RETURN_STRING_LITERAL  // undef for jumbo builds
diff --git a/quic/core/quic_versions_test.cc b/quic/core/quic_versions_test.cc
index 283113f..3521e5b 100644
--- a/quic/core/quic_versions_test.cc
+++ b/quic/core/quic_versions_test.cc
@@ -280,7 +280,6 @@
   QuicTransportVersionVector all_versions = AllSupportedTransportVersions();
   static_assert(QUIC_ARRAYSIZE(kSupportedTransportVersions) == 6u,
                 "Supported versions out of sync");
-  SetQuicReloadableFlag(quic_enable_version_50, true);
   SetQuicReloadableFlag(quic_enable_version_99, true);
   ParsedQuicVersionVector parsed_versions;
   for (QuicTransportVersion version : all_versions) {
@@ -303,7 +302,6 @@
   QuicTransportVersionVector all_versions = AllSupportedTransportVersions();
   static_assert(QUIC_ARRAYSIZE(kSupportedTransportVersions) == 6u,
                 "Supported versions out of sync");
-  SetQuicReloadableFlag(quic_enable_version_50, true);
   SetQuicReloadableFlag(quic_enable_version_99, false);
   ParsedQuicVersionVector parsed_versions;
   for (QuicTransportVersion version : all_versions) {
@@ -322,38 +320,18 @@
   ASSERT_EQ(expected_parsed_versions, FilterSupportedVersions(parsed_versions));
 }
 
-TEST_F(QuicVersionsTest, FilterSupportedTransportVersionsNo50) {
-  QuicTransportVersionVector all_versions = AllSupportedTransportVersions();
-  SetQuicReloadableFlag(quic_enable_version_50, false);
-  SetQuicReloadableFlag(quic_enable_version_99, false);
-  ParsedQuicVersionVector parsed_versions;
-  for (QuicTransportVersion version : all_versions) {
-    parsed_versions.push_back(ParsedQuicVersion(PROTOCOL_QUIC_CRYPTO, version));
-  }
-  QuicTransportVersionVector expected_versions = {
-      QUIC_VERSION_49, QUIC_VERSION_48, QUIC_VERSION_46, QUIC_VERSION_43};
-  ParsedQuicVersionVector expected_parsed_versions;
-  for (QuicTransportVersion version : expected_versions) {
-    expected_parsed_versions.push_back(
-        ParsedQuicVersion(PROTOCOL_QUIC_CRYPTO, version));
-  }
-
-  ASSERT_EQ(expected_versions, FilterSupportedTransportVersions(all_versions));
-  ASSERT_EQ(expected_parsed_versions, FilterSupportedVersions(parsed_versions));
-}
-
 TEST_F(QuicVersionsTest, FilterSupportedTransportVersionsNoFlags) {
   QuicTransportVersionVector all_versions = AllSupportedTransportVersions();
   static_assert(QUIC_ARRAYSIZE(kSupportedTransportVersions) == 6u,
                 "Supported versions out of sync");
-  SetQuicReloadableFlag(quic_enable_version_50, false);
   SetQuicReloadableFlag(quic_enable_version_99, false);
   ParsedQuicVersionVector parsed_versions;
   for (QuicTransportVersion version : all_versions) {
     parsed_versions.push_back(ParsedQuicVersion(PROTOCOL_QUIC_CRYPTO, version));
   }
   QuicTransportVersionVector expected_versions = {
-      QUIC_VERSION_49, QUIC_VERSION_48, QUIC_VERSION_46, QUIC_VERSION_43};
+      QUIC_VERSION_50, QUIC_VERSION_49, QUIC_VERSION_48, QUIC_VERSION_46,
+      QUIC_VERSION_43};
   ParsedQuicVersionVector expected_parsed_versions;
   for (QuicTransportVersion version : expected_versions) {
     expected_parsed_versions.push_back(
@@ -446,37 +424,15 @@
   static_assert(QUIC_ARRAYSIZE(kSupportedTransportVersions) == 6u,
                 "Supported versions out of sync");
   SetQuicReloadableFlag(quic_supports_tls_handshake, true);
-  ParsedQuicVersion parsed_version_q050 =
-      ParsedQuicVersion(PROTOCOL_QUIC_CRYPTO, QUIC_VERSION_50);
-  ParsedQuicVersion parsed_version_t050 =
-      ParsedQuicVersion(PROTOCOL_TLS1_3, QUIC_VERSION_50);
   ParsedQuicVersion parsed_version_t099 =
       ParsedQuicVersion(PROTOCOL_TLS1_3, QUIC_VERSION_99);
   SetQuicReloadableFlag(quic_supports_tls_handshake, false);
-  SetQuicReloadableFlag(quic_enable_version_50, false);
   SetQuicReloadableFlag(quic_enable_version_99, false);
 
   {
     QuicFlagSaver flag_saver;
-    QuicEnableVersion(parsed_version_q050);
-    EXPECT_FALSE(GetQuicReloadableFlag(quic_supports_tls_handshake));
-    EXPECT_TRUE(GetQuicReloadableFlag(quic_enable_version_50));
-    EXPECT_FALSE(GetQuicReloadableFlag(quic_enable_version_99));
-  }
-
-  {
-    QuicFlagSaver flag_saver;
-    QuicEnableVersion(parsed_version_t050);
-    EXPECT_TRUE(GetQuicReloadableFlag(quic_supports_tls_handshake));
-    EXPECT_TRUE(GetQuicReloadableFlag(quic_enable_version_50));
-    EXPECT_FALSE(GetQuicReloadableFlag(quic_enable_version_99));
-  }
-
-  {
-    QuicFlagSaver flag_saver;
     QuicEnableVersion(parsed_version_t099);
     EXPECT_TRUE(GetQuicReloadableFlag(quic_supports_tls_handshake));
-    EXPECT_FALSE(GetQuicReloadableFlag(quic_enable_version_50));
     EXPECT_TRUE(GetQuicReloadableFlag(quic_enable_version_99));
   }
 }
diff --git a/quic/quartc/quartc_factory.cc b/quic/quartc/quartc_factory.cc
index ad677fd..ffbb95e 100644
--- a/quic/quartc/quartc_factory.cc
+++ b/quic/quartc/quartc_factory.cc
@@ -63,9 +63,6 @@
   // Fixes behavior of StopReading() with level-triggered stream sequencers.
   SetQuicReloadableFlag(quic_stop_reading_when_level_triggered, true);
 
-  // Enable version 50 to be compatible with the latest version of Chrome.
-  SetQuicReloadableFlag(quic_enable_version_50, true);
-
   // Ensure that we don't drop data because QUIC streams refuse to buffer it.
   // TODO(b/120099046):  Replace this with correct handling of WriteMemSlices().
   SetQuicFlag(FLAGS_quic_buffered_data_threshold,
@@ -95,7 +92,7 @@
 
   // In exoblaze this may return false. DCHECK to avoid problems caused by
   // incorrect flags configuration.
-  DCHECK(GetQuicReloadableFlag(quic_enable_version_50))
+  DCHECK(GetQuicReloadableFlag(quic_stop_reading_when_level_triggered))
       << "Your build does not support quic reloadable flags and shouldn't "
          "place Quartc calls";