Add support to QUIC for QUIC_VERSION_8: for RSA-PSS signatures, set

net/quic/crypto/proof_source.h

Index: net/quic/crypto/proof_source.h
===================================================================
--- net/quic/crypto/proof_source.h	(revision 216255)
+++ net/quic/crypto/proof_source.h	(working copy)
@@ -9,6 +9,7 @@
 #include <vector>
 
 #include "net/base/net_export.h"
+#include "net/quic/quic_protocol.h"
 
 namespace net {
 
@@ -27,6 +28,9 @@
   //
   // The signature uses SHA-256 as the hash function when the key is ECDSA.
   //
+  // |version| is the QUIC version for the connection. TODO(wtc): Remove once
+  // QUIC_VERSION_7 and before are removed.
+  //
   // |out_certs| is a pointer to a pointer, not a pointer to an array.
   //
   // The number of certificate chains is expected to be small and fixed thus
@@ -42,7 +46,8 @@
   // used.
   //
   // This function may be called concurrently.
-  virtual bool GetProof(const std::string& hostname,
+  virtual bool GetProof(QuicVersion version,
+                        const std::string& hostname,
                         const std::string& server_config,
                         bool ecdsa_ok,
                         const std::vector<std::string>** out_certs,