Implement referred Token Bindings

net/http/http_network_transaction.h

Index: net/http/http_network_transaction.h
diff --git a/net/http/http_network_transaction.h b/net/http/http_network_transaction.h
index 5b554afd8e8805ae16a931134ba3d7dd52fbc6d0..2b9f5162a3972012a701e1174e32532a51959b45 100644
--- a/net/http/http_network_transaction.h
+++ b/net/http/http_network_transaction.h
@@ -341,9 +341,11 @@ class NET_EXPORT_PRIVATE HttpNetworkTransaction
   // The SSLFailureState which caused the last TLS version fallback.
   SSLFailureState fallback_failure_state_;
 
-  // Key to use for signing message in Token Binding header.
-  scoped_ptr<crypto::ECPrivateKey> token_binding_key_;
-  // Object to manage lookup of |token_binding_key_|.
+  // Keys to use for signing message in Token Binding header.
+  scoped_ptr<crypto::ECPrivateKey> provided_token_binding_key_;
+  scoped_ptr<crypto::ECPrivateKey> referred_token_binding_key_;
+  // Object to manage lookup of |provided_token_binding_key_| and
+  // |referred_token_binding_key_|.
   ChannelIDService::Request token_binding_request_;
 
   HttpRequestHeaders request_headers_;