Add quic::ProofSource::TicketCrypter interface

The ProofSource::TicketCrypter interface will be used by
TlsServerHandshaker to encrypt and decrypt session tickets. This is needed
to support TLS session resumption and 0-RTT in QUIC.

gfe-relnote: add unused method to quic::ProofSource interface
PiperOrigin-RevId: 308132437
Change-Id: I1176369e1b3d286d299303aec07d46292fddf982
diff --git a/quic/test_tools/failing_proof_source.h b/quic/test_tools/failing_proof_source.h
index 36e2398..69a3e7a 100644
--- a/quic/test_tools/failing_proof_source.h
+++ b/quic/test_tools/failing_proof_source.h
@@ -30,6 +30,8 @@
       uint16_t signature_algorithm,
       quiche::QuicheStringPiece in,
       std::unique_ptr<SignatureCallback> callback) override;
+
+  TicketCrypter* SessionTicketCrypter() override { return nullptr; }
 };
 
 }  // namespace test