Add alpn to interface QuicTestServer::SessionFactory::CreateSession.

PiperOrigin-RevId: 532874804
diff --git a/quiche/quic/test_tools/quic_test_server.cc b/quiche/quic/test_tools/quic_test_server.cc
index 272f237..fc95413 100644
--- a/quiche/quic/test_tools/quic_test_server.cc
+++ b/quiche/quic/test_tools/quic_test_server.cc
@@ -86,7 +86,7 @@
 
   std::unique_ptr<QuicSession> CreateQuicSession(
       QuicConnectionId id, const QuicSocketAddress& self_address,
-      const QuicSocketAddress& peer_address, absl::string_view /*alpn*/,
+      const QuicSocketAddress& peer_address, absl::string_view alpn,
       const ParsedQuicVersion& version,
       const ParsedClientHello& /*parsed_chlo*/) override {
     QuicReaderMutexLock lock(&factory_lock_);
@@ -111,7 +111,7 @@
     } else {
       session = session_factory_->CreateSession(
           config(), connection, this, session_helper(), crypto_config(),
-          compressed_certs_cache(), server_backend());
+          compressed_certs_cache(), server_backend(), alpn);
     }
     if (VersionUsesHttp3(version.transport_version)) {
       QUICHE_DCHECK(session->allow_extended_connect());
diff --git a/quiche/quic/test_tools/quic_test_server.h b/quiche/quic/test_tools/quic_test_server.h
index c0be6f0..4bf629a 100644
--- a/quiche/quic/test_tools/quic_test_server.h
+++ b/quiche/quic/test_tools/quic_test_server.h
@@ -33,7 +33,8 @@
         QuicCryptoServerStreamBase::Helper* helper,
         const QuicCryptoServerConfig* crypto_config,
         QuicCompressedCertsCache* compressed_certs_cache,
-        QuicSimpleServerBackend* quic_simple_server_backend) = 0;
+        QuicSimpleServerBackend* quic_simple_server_backend,
+        absl::string_view alpn) = 0;
   };
 
   // Factory for creating QuicSimpleServerStreams.