Unblock quic_stop_sending_legacy_version_info

We realized that a few tests were failing when the values of quic_stop_sending_legacy_version_info and quic_stop_parsing_legacy_version_info were different, so quic_stop_sending_legacy_version_info was blocked in cl/853491571.

This CL fixes the test issue and reverts cl/853491571.

We confirmed that tests pass by running all four combinations via:

```
blaze test //third_party/quic/core/crypto:transport_parameters_test --test_arg=--gfe2_restart_flag_quic_stop_parsing_legacy_version_info=true --test_arg=--gfe2_restart_flag_quic_stop_sending_legacy_version_info=true && blaze test //third_party/quic/core/crypto:transport_parameters_test --test_arg=--gfe2_restart_flag_quic_stop_parsing_legacy_version_info=true --test_arg=--gfe2_restart_flag_quic_stop_sending_legacy_version_info=false && blaze test //third_party/quic/core/crypto:transport_parameters_test --test_arg=--gfe2_restart_flag_quic_stop_parsing_legacy_version_info=false --test_arg=--gfe2_restart_flag_quic_stop_sending_legacy_version_info=true && blaze test //third_party/quic/core/crypto:transport_parameters_test --test_arg=--gfe2_restart_flag_quic_stop_parsing_legacy_version_info=false --test_arg=--gfe2_restart_flag_quic_stop_sending_legacy_version_info=false
```

PiperOrigin-RevId: 855471392

Author: DavidSchinazi

quiche/common/quiche_feature_flags_list.h

@@ -72,7 +72,7 @@ QUICHE_FLAG(bool, quiche_reloadable_flag_reset_content_length_status_when_removi
 QUICHE_FLAG(bool, quiche_restart_flag_quic_dispatcher_close_connection_on_invalid_ack, false, false, "An invalid ack is an ack that the peer sent for a packet that was not sent by the dispatcher. If true, the dispatcher will close the connection if it receives an invalid ack.")
 QUICHE_FLAG(bool, quiche_restart_flag_quic_shed_tls_handshake_config, false, false, "If true, QUIC connections will call SSL_set_shed_handshake_config to drop BoringSSL handshake state after the handshake finishes in order to save memory.")
 QUICHE_FLAG(bool, quiche_restart_flag_quic_stop_parsing_legacy_version_info, false, false, "If true, disable parsing the legacy version information transport parameter.")
-QUICHE_FLAG(bool, quiche_restart_flag_quic_stop_sending_legacy_version_info, false, false, "If true, disable sending the legacy version information transport parameter.")
+QUICHE_FLAG(bool, quiche_restart_flag_quic_stop_sending_legacy_version_info, false, true, "If true, disable sending the legacy version information transport parameter.")
 QUICHE_FLAG(bool, quiche_restart_flag_quic_support_release_time_for_gso, false, false, "If true, QuicGsoBatchWriter will support release time if it is available and the process has the permission to do so.")
 QUICHE_FLAG(bool, quiche_restart_flag_quic_testonly_default_false, false, false, "A testonly restart flag that will always default to false.")
 QUICHE_FLAG(bool, quiche_restart_flag_quic_testonly_default_true, true, true, "A testonly restart flag that will always default to true.")

quiche/quic/core/crypto/transport_parameters_test.cc

@@ -52,6 +52,8 @@ const auto kCustomParameter1 =
 const char* kCustomParameter1Value = "foo";
 const auto kCustomParameter2 =
     static_cast<TransportParameters::TransportParameterId>(0xff34);
+const auto kLegacyVersionInfoParameter =
+    static_cast<TransportParameters::TransportParameterId>(0x4752);
 const char* kCustomParameter2Value = "bar";
 
 const char kFakeGoogleHandshakeMessage[] =
@@ -325,8 +327,7 @@ TEST_P(TransportParametersTest, CopyConstructor) {
 TEST_P(TransportParametersTest, RoundTripClient) {
   TransportParameters orig_params;
   orig_params.perspective = Perspective::IS_CLIENT;
-  if (!GetQuicRestartFlag(quic_stop_parsing_legacy_version_info) ||
-      !GetQuicRestartFlag(quic_stop_sending_legacy_version_info)) {
+  if (!GetQuicRestartFlag(quic_stop_sending_legacy_version_info)) {
     orig_params.legacy_version_information =
         CreateFakeLegacyVersionInformationClient();
   }
@@ -373,14 +374,18 @@ TEST_P(TransportParametersTest, RoundTripClient) {
       << error_details;
   EXPECT_TRUE(error_details.empty());
   RemoveGreaseParameters(&new_params);
+  if (GetQuicRestartFlag(quic_stop_parsing_legacy_version_info) &&
+      !GetQuicRestartFlag(quic_stop_sending_legacy_version_info)) {
+    orig_params.legacy_version_information.reset();
+    new_params.custom_parameters.erase(kLegacyVersionInfoParameter);
+  }
   EXPECT_EQ(new_params, orig_params);
 }
 
 TEST_P(TransportParametersTest, RoundTripServer) {
   TransportParameters orig_params;
   orig_params.perspective = Perspective::IS_SERVER;
-  if (!GetQuicRestartFlag(quic_stop_parsing_legacy_version_info) ||
-      !GetQuicRestartFlag(quic_stop_sending_legacy_version_info)) {
+  if (!GetQuicRestartFlag(quic_stop_sending_legacy_version_info)) {
     orig_params.legacy_version_information =
         CreateFakeLegacyVersionInformationServer();
   }
@@ -423,6 +428,11 @@ TEST_P(TransportParametersTest, RoundTripServer) {
       << error_details;
   EXPECT_TRUE(error_details.empty());
   RemoveGreaseParameters(&new_params);
+  if (GetQuicRestartFlag(quic_stop_parsing_legacy_version_info) &&
+      !GetQuicRestartFlag(quic_stop_sending_legacy_version_info)) {
+    orig_params.legacy_version_information.reset();
+    new_params.custom_parameters.erase(kLegacyVersionInfoParameter);
+  }
   EXPECT_EQ(new_params, orig_params);
 }
 
@@ -654,8 +664,7 @@ TEST_P(TransportParametersTest, ParseClientParams) {
       << error_details;
   EXPECT_TRUE(error_details.empty());
   EXPECT_EQ(Perspective::IS_CLIENT, new_params.perspective);
-  if (!GetQuicRestartFlag(quic_stop_parsing_legacy_version_info) ||
-      !GetQuicRestartFlag(quic_stop_sending_legacy_version_info)) {
+  if (!GetQuicRestartFlag(quic_stop_parsing_legacy_version_info)) {
     ASSERT_TRUE(new_params.legacy_version_information.has_value());
     EXPECT_EQ(kFakeVersionLabel,
               new_params.legacy_version_information.value().version);
@@ -921,8 +930,7 @@ TEST_P(TransportParametersTest, ParseServerParams) {
       << error_details;
   EXPECT_TRUE(error_details.empty());
   EXPECT_EQ(Perspective::IS_SERVER, new_params.perspective);
-  if (!GetQuicRestartFlag(quic_stop_parsing_legacy_version_info) ||
-      !GetQuicRestartFlag(quic_stop_sending_legacy_version_info)) {
+  if (!GetQuicRestartFlag(quic_stop_parsing_legacy_version_info)) {
     ASSERT_TRUE(new_params.legacy_version_information.has_value());
     EXPECT_EQ(kFakeVersionLabel,
               new_params.legacy_version_information.value().version);
@@ -1055,8 +1063,7 @@ TEST_P(TransportParametersTest, VeryLongCustomParameter) {
   std::string custom_value(70000, '?');
   TransportParameters orig_params;
   orig_params.perspective = Perspective::IS_CLIENT;
-  if (!GetQuicRestartFlag(quic_stop_parsing_legacy_version_info) ||
-      !GetQuicRestartFlag(quic_stop_sending_legacy_version_info)) {
+  if (!GetQuicRestartFlag(quic_stop_sending_legacy_version_info)) {
     orig_params.legacy_version_information =
         CreateFakeLegacyVersionInformationClient();
   }
@@ -1073,6 +1080,11 @@ TEST_P(TransportParametersTest, VeryLongCustomParameter) {
       << error_details;
   EXPECT_TRUE(error_details.empty());
   RemoveGreaseParameters(&new_params);
+  if (GetQuicRestartFlag(quic_stop_parsing_legacy_version_info) &&
+      !GetQuicRestartFlag(quic_stop_sending_legacy_version_info)) {
+    orig_params.legacy_version_information.reset();
+    new_params.custom_parameters.erase(kLegacyVersionInfoParameter);
+  }
   EXPECT_EQ(new_params, orig_params);
 }
 
@@ -1126,8 +1138,7 @@ TEST_P(TransportParametersTest, SerializationOrderIsRandom) {
 TEST_P(TransportParametersTest, Degrease) {
   TransportParameters orig_params;
   orig_params.perspective = Perspective::IS_CLIENT;
-  if (!GetQuicRestartFlag(quic_stop_parsing_legacy_version_info) ||
-      !GetQuicRestartFlag(quic_stop_sending_legacy_version_info)) {
+  if (!GetQuicRestartFlag(quic_stop_sending_legacy_version_info)) {
     orig_params.legacy_version_information =
         CreateFakeLegacyVersionInformationClient();
   }
@@ -1178,6 +1189,11 @@ TEST_P(TransportParametersTest, Degrease) {
   EXPECT_NE(new_params, orig_params);
 
   DegreaseTransportParameters(new_params);
+  if (GetQuicRestartFlag(quic_stop_parsing_legacy_version_info) &&
+      !GetQuicRestartFlag(quic_stop_sending_legacy_version_info)) {
+    orig_params.legacy_version_information.reset();
+    new_params.custom_parameters.erase(kLegacyVersionInfoParameter);
+  }
   EXPECT_EQ(new_params, orig_params);
 }