Refactoring output of ProofSource::GetProof (no functional changes).

net/quic/core/quic_crypto_server_stream_test.cc

Index: net/quic/core/quic_crypto_server_stream_test.cc
diff --git a/net/quic/core/quic_crypto_server_stream_test.cc b/net/quic/core/quic_crypto_server_stream_test.cc
index 27c9abcb2cdb4490fc65b63410de32439275ce1c..b5ed5bf53f863aa7b237673d39daf2ef00369912 100644
--- a/net/quic/core/quic_crypto_server_stream_test.cc
+++ b/net/quic/core/quic_crypto_server_stream_test.cc
@@ -585,8 +585,7 @@ class FailingProofSource : public ProofSource {
                 StringPiece chlo_hash,
                 const QuicTagVector& connection_options,
                 scoped_refptr<ProofSource::Chain>* out_chain,
-                string* out_signature,
-                string* out_leaf_cert_sct) override {
+                QuicCryptoProof* out_proof) override {
     return false;
   }
 
@@ -597,7 +596,7 @@ class FailingProofSource : public ProofSource {
                 StringPiece chlo_hash,
                 const QuicTagVector& connection_options,
                 std::unique_ptr<Callback> callback) override {
-    callback->Run(false, nullptr, "", "", nullptr);
+    callback->Run(false, nullptr, QuicCryptoProof(), nullptr);
   }
 };