Do not use version flags in Chrome QUIC code

This CL replaces instances of flag-setting
with calls to QuicEnableVersion and
QuicDisableVersion. Some tests were using
version flags as any flags, and those have
been replaced with test flags. This will make
changing versions easier.

R=renjietang@chromium.org

Change-Id: Id96f2fc92a10de3e410b4995190582e657dc57dd
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2253209
Auto-Submit: David Schinazi <dschinazi@chromium.org>
Reviewed-by: Renjie Tang <renjietang@chromium.org>
Commit-Queue: David Schinazi <dschinazi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#780372}

components/cronet/url_request_context_config_unittest.cc

@@ -68,10 +68,8 @@ TEST(URLRequestContextConfigTest, TestExperimentalOptionParsing) {
   options.SetPath({"QUIC", "connection_options"}, base::Value("TIME,TBBR,REJ"));
   options.SetPath(
       {"QUIC", "set_quic_flags"},
-      base::Value(
-          "FLAGS_quic_max_aggressive_retransmittable_on_wire_ping_count=5,"
-          "FLAGS_quic_reloadable_flag_quic_enable_version_draft_29=true,"
-          "FLAGS_quic_reloadable_flag_quic_disable_version_draft_27=true"));
+      base::Value("FLAGS_quic_reloadable_flag_quic_testonly_default_false=true,"
+                  "FLAGS_quic_restart_flag_quic_testonly_default_true=false"));
   options.SetPath({"AsyncDNS", "enable"}, base::Value(true));
   options.SetPath({"NetworkErrorLogging", "enable"}, base::Value(true));
   options.SetPath({"NetworkErrorLogging", "preloaded_report_to_headers"},
@@ -143,9 +141,8 @@ TEST(URLRequestContextConfigTest, TestExperimentalOptionParsing) {
   EXPECT_TRUE(base::JSONWriter::Write(options, &options_json));
 
   // Initialize QUIC flags set by the config.
-  FLAGS_quic_max_aggressive_retransmittable_on_wire_ping_count = 0;
-  FLAGS_quic_reloadable_flag_quic_enable_version_draft_29 = false;
-  FLAGS_quic_reloadable_flag_quic_disable_version_draft_27 = false;
+  FLAGS_quic_reloadable_flag_quic_testonly_default_false = false;
+  FLAGS_quic_restart_flag_quic_testonly_default_true = true;
 
   URLRequestContextConfig config(
       // Enable QUIC.
@@ -196,9 +193,9 @@ TEST(URLRequestContextConfigTest, TestExperimentalOptionParsing) {
   quic_connection_options.push_back(quic::kREJ);
   EXPECT_EQ(quic_connection_options, quic_params->connection_options);
 
-  EXPECT_EQ(FLAGS_quic_max_aggressive_retransmittable_on_wire_ping_count, 5);
-  EXPECT_TRUE(FLAGS_quic_reloadable_flag_quic_enable_version_draft_29);
-  EXPECT_TRUE(FLAGS_quic_reloadable_flag_quic_disable_version_draft_27);
+  // Check QUIC flags.
+  EXPECT_TRUE(FLAGS_quic_reloadable_flag_quic_testonly_default_false);
+  EXPECT_FALSE(FLAGS_quic_restart_flag_quic_testonly_default_true);
 
   // Check Custom QUIC User Agent Id.
   EXPECT_EQ("Custom QUIC UAID", quic_params->user_agent_id);

components/network_session_configurator/browser/network_session_configurator_unittest.cc

@@ -597,19 +597,19 @@ TEST_F(NetworkSessionConfiguratorTest, QuicHostAllowlistEmpty) {
 }
 
 TEST_F(NetworkSessionConfiguratorTest, QuicFlags) {
-  FLAGS_quic_reloadable_flag_quic_enable_version_draft_29 = false;
-  FLAGS_quic_reloadable_flag_quic_disable_version_draft_27 = false;
+  FLAGS_quic_reloadable_flag_quic_testonly_default_false = false;
+  FLAGS_quic_restart_flag_quic_testonly_default_true = true;
   std::map<std::string, std::string> field_trial_params;
   field_trial_params["set_quic_flags"] =
-      "FLAGS_quic_reloadable_flag_quic_enable_version_draft_29=true,"
-      "FLAGS_quic_reloadable_flag_quic_disable_version_draft_27=true";
+      "FLAGS_quic_reloadable_flag_quic_testonly_default_false=true,"
+      "FLAGS_quic_restart_flag_quic_testonly_default_true=false";
   variations::AssociateVariationParams("QUIC", "Enabled", field_trial_params);
   base::FieldTrialList::CreateFieldTrial("QUIC", "Enabled");
 
   ParseFieldTrials();
 
-  EXPECT_TRUE(FLAGS_quic_reloadable_flag_quic_enable_version_draft_29);
-  EXPECT_TRUE(FLAGS_quic_reloadable_flag_quic_disable_version_draft_27);
+  EXPECT_TRUE(FLAGS_quic_reloadable_flag_quic_testonly_default_false);
+  EXPECT_FALSE(FLAGS_quic_restart_flag_quic_testonly_default_true);
 }
 
 TEST_F(NetworkSessionConfiguratorTest, Http2SettingsFromFieldTrialParams) {

net/quic/quic_flags_list.h

@@ -236,6 +236,15 @@ QUIC_FLAG(bool, FLAGS_quic_reloadable_flag_quic_disable_version_q050, false)
 // A testonly reloadable flag that will always default to false.
 QUIC_FLAG(bool, FLAGS_quic_reloadable_flag_quic_testonly_default_false, false)
 
+// A testonly reloadable flag that will always default to true.
+QUIC_FLAG(bool, FLAGS_quic_reloadable_flag_quic_testonly_default_true, true)
+
+// A testonly restart flag that will always default to false.
+QUIC_FLAG(bool, FLAGS_quic_restart_flag_quic_testonly_default_false, false)
+
+// A testonly restart flag that will always default to true.
+QUIC_FLAG(bool, FLAGS_quic_restart_flag_quic_testonly_default_true, true)
+
 // In BBR, slow pacing rate if it is likely causing overshoot.
 QUIC_FLAG(
     bool,

net/quic/quic_transport_end_to_end_test.cc

@@ -76,8 +76,10 @@ class TestConnectionHelper : public quic::QuicConnectionHelperInterface {
 class QuicTransportEndToEndTest : public TestWithTaskEnvironment {
  public:
   QuicTransportEndToEndTest() {
-    quic::QuicEnableVersion(
-        QuicTransportClient::QuicVersionsForWebTransportOriginTrial()[0]);
+    for (const quic::ParsedQuicVersion& version :
+         QuicTransportClient::QuicVersionsForWebTransportOriginTrial()) {
+      quic::QuicEnableVersion(version);
+    }
     origin_ = url::Origin::Create(GURL{"https://example.org"});
     isolation_key_ = NetworkIsolationKey(origin_, origin_);
 
@@ -265,8 +267,9 @@ TEST_F(QuicTransportEndToEndTest, CertificateFingerprintMismatch) {
 }
 
 TEST_F(QuicTransportEndToEndTest, OldVersion) {
-  SetQuicReloadableFlag(quic_enable_version_draft_29, false);
-  SetQuicReloadableFlag(quic_disable_version_draft_27, false);
+  // Ensure all WebTransport versions are enabled except the first one.
+  quic::QuicDisableVersion(
+      QuicTransportClient::QuicVersionsForWebTransportOriginTrial().front());
 
   StartServer();
   client_ = std::make_unique<QuicTransportClient>(
@@ -280,8 +283,11 @@ TEST_F(QuicTransportEndToEndTest, OldVersion) {
 }
 
 TEST_F(QuicTransportEndToEndTest, NoCommonVersion) {
-  SetQuicReloadableFlag(quic_enable_version_draft_29, false);
-  SetQuicReloadableFlag(quic_disable_version_draft_27, true);
+  // Disable all WebTransport versions.
+  for (const quic::ParsedQuicVersion& version :
+       QuicTransportClient::QuicVersionsForWebTransportOriginTrial()) {
+    quic::QuicDisableVersion(version);
+  }
 
   StartServer();
   client_ = std::make_unique<QuicTransportClient>(