gfe-relnote: Introduce QUIC_VERSION_50, protected by quic_enable_version_50

Version 50 uses header protection, initial obfuscators, and IETF IV construction.

PiperOrigin-RevId: 273780903
Change-Id: I2750db51f2a6e30d93ab52e9978129353134e5ee
diff --git a/quic/core/quic_dispatcher_test.cc b/quic/core/quic_dispatcher_test.cc
index 280d110..abae0f2 100644
--- a/quic/core/quic_dispatcher_test.cc
+++ b/quic/core/quic_dispatcher_test.cc
@@ -930,12 +930,13 @@
 }
 
 TEST_F(QuicDispatcherTest, SupportedTransportVersionsChangeInFlight) {
-  static_assert(QUIC_ARRAYSIZE(kSupportedTransportVersions) == 7u,
+  static_assert(QUIC_ARRAYSIZE(kSupportedTransportVersions) == 8u,
                 "Supported versions out of sync");
   SetQuicReloadableFlag(quic_disable_version_39, false);
   SetQuicReloadableFlag(quic_enable_version_47, true);
   SetQuicReloadableFlag(quic_enable_version_48_2, true);
   SetQuicReloadableFlag(quic_enable_version_49, true);
+  SetQuicReloadableFlag(quic_enable_version_50, true);
   SetQuicReloadableFlag(quic_enable_version_99, true);
 
   VerifyVersionNotSupported(QuicVersionReservedForNegotiation());
@@ -944,6 +945,16 @@
                                            QuicVersionMin().transport_version));
   VerifyVersionSupported(QuicVersionMax());
 
+  // Turn off version 50.
+  SetQuicReloadableFlag(quic_enable_version_50, false);
+  VerifyVersionNotSupported(
+      ParsedQuicVersion(PROTOCOL_QUIC_CRYPTO, QUIC_VERSION_50));
+
+  // Turn on version 50.
+  SetQuicReloadableFlag(quic_enable_version_50, true);
+  VerifyVersionSupported(
+      ParsedQuicVersion(PROTOCOL_QUIC_CRYPTO, QUIC_VERSION_50));
+
   // Turn off version 49.
   SetQuicReloadableFlag(quic_enable_version_49, false);
   VerifyVersionNotSupported(
@@ -986,7 +997,7 @@
 }
 
 TEST_F(QuicDispatcherTest, RejectDeprecatedVersionsWithVersionNegotiation) {
-  static_assert(QUIC_ARRAYSIZE(kSupportedTransportVersions) == 7u,
+  static_assert(QUIC_ARRAYSIZE(kSupportedTransportVersions) == 8u,
                 "Please add deprecated versions to this test");
   QuicSocketAddress client_address(QuicIpAddress::Loopback4(), 1);
   CreateTimeWaitListManager();