Log when client nonce is invalid. No functional change. Not flag protected.

net/quic/crypto/quic_crypto_server_config.cc

Index: net/quic/crypto/quic_crypto_server_config.cc
diff --git a/net/quic/crypto/quic_crypto_server_config.cc b/net/quic/crypto/quic_crypto_server_config.cc
index 00f20cbfa1c60b25c76fe5d40fea94fa20d7674a..3ef62d2f1e12b82ff5461b488ed0bd873554bbc2 100644
--- a/net/quic/crypto/quic_crypto_server_config.cc
+++ b/net/quic/crypto/quic_crypto_server_config.cc
@@ -1064,6 +1064,7 @@ void QuicCryptoServerConfig::EvaluateClientHello(
       info->client_nonce.size() != kNonceSize) {
     info->reject_reasons.push_back(CLIENT_NONCE_INVALID_FAILURE);
     // Invalid client nonce.
+    LOG(ERROR) << "Invalid client nonce: " << client_hello.DebugString();
     DVLOG(1) << "Invalid client nonce.";
     if (FLAGS_use_early_return_when_verifying_chlo) {
       helper.ValidationComplete(QUIC_NO_ERROR, "");