Along with sending the SCUP message, this CL includes small fixes which

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 cc25570af6bd48ededeead3c1096b6145ba37710..b97bd68f6ef00150bea1ee746b8c4f66f76d477a 100644
--- a/net/quic/crypto/crypto_handshake.h
+++ b/net/quic/crypto/crypto_handshake.h
@@ -9,6 +9,7 @@
 #include <vector>
 
 #include "base/memory/scoped_ptr.h"
+#include "base/strings/string_piece.h"
 #include "net/base/net_export.h"
 #include "net/quic/quic_protocol.h"
 
@@ -124,6 +125,13 @@ struct NET_EXPORT_PRIVATE QuicCryptoNegotiatedParameters {
   // bytes of x coordinate, followed by 32 bytes of y coordinate. Both values
   // are big-endian and the pair is a P-256 public key.
   std::string channel_id;
+
+  // Used when generating proof signature when sending server config updates.
+  bool x509_ecdsa_supported;
+
+  // Used to generate cert chain when sending server config updates.
+  base::StringPiece client_common_set_hashes;
+  base::StringPiece client_cached_cert_hashes;
 };
 
 // QuicCryptoConfig contains common configuration between clients and servers.