Clear the QUIC cached proof when a client receives a REJ w/o a PROF tag.

net/quic/crypto/crypto_handshake.h

Index: net/quic/crypto/crypto_handshake.h
diff --git a/net/quic/crypto/crypto_handshake.h b/net/quic/crypto/crypto_handshake.h
index fdc92a0fc382e9fcf47b9092d1f03635e41b89b9..8d954b6e769c2b42145da1dc9599df2724f7874a 100644
--- a/net/quic/crypto/crypto_handshake.h
+++ b/net/quic/crypto/crypto_handshake.h
@@ -266,6 +266,9 @@ class NET_EXPORT_PRIVATE QuicCryptoClientConfig : public QuicCryptoConfig {
     void SetProof(const std::vector<std::string>& certs,
                   base::StringPiece signature);
 
+    // Clears the certificate chain and signature and invalidates the proof.
+    void ClearProof();
+
     // SetProofValid records that the certificate chain and signature have been
     // validated and that it's safe to assume that the server is legitimate.
     // (Note: this does not check the chain or signature.)