Cleanup AuthenticatorMethod usage.

remoting/protocol/pairing_client_authenticator.cc

Index: remoting/protocol/pairing_client_authenticator.cc
diff --git a/remoting/protocol/pairing_client_authenticator.cc b/remoting/protocol/pairing_client_authenticator.cc
index 747654c07835fcaa780e7618bddade9c836a55f4..c4e0b291bb63a6d33be683365bcac280e42e19ca 100644
--- a/remoting/protocol/pairing_client_authenticator.cc
+++ b/remoting/protocol/pairing_client_authenticator.cc
@@ -7,8 +7,7 @@
 #include "base/bind.h"
 #include "base/logging.h"
 #include "remoting/base/constants.h"
-#include "remoting/base/rsa_key_pair.h"
-#include "remoting/protocol/authentication_method.h"
+#include "remoting/protocol/auth_util.h"
 #include "remoting/protocol/channel_authenticator.h"
 #include "third_party/webrtc/libjingle/xmllite/xmlelement.h"
 
@@ -20,12 +19,12 @@ PairingClientAuthenticator::PairingClientAuthenticator(
     const std::string& paired_secret,
     const CreateBaseAuthenticatorCallback& create_base_authenticator_callback,
     const FetchSecretCallback& fetch_pin_callback,
-    const std::string& authentication_tag)
+    const std::string& host_id)
     : client_id_(client_id),
       paired_secret_(paired_secret),
       create_base_authenticator_callback_(create_base_authenticator_callback),
       fetch_pin_callback_(fetch_pin_callback),
-      authentication_tag_(authentication_tag),
+      host_id_(host_id),
       weak_factory_(this) {
   spake2_authenticator_ =
       create_base_authenticator_callback_.Run(paired_secret_, MESSAGE_READY);
@@ -72,9 +71,7 @@ void PairingClientAuthenticator::OnPinFetched(
   DCHECK(!spake2_authenticator_);
   waiting_for_pin_ = false;
   spake2_authenticator_ = create_base_authenticator_callback_.Run(
-      ApplySharedSecretHashFunction(HashFunction::HMAC_SHA256,
-                                    authentication_tag_, pin),
-      initial_state);
+      GetSharedSecretHash(host_id_, pin), initial_state);
   resume_callback.Run();
 }