Simplify AuthenticationMethod type and PIN hash handling.

remoting/protocol/me2me_host_authenticator_factory.h

Index: remoting/protocol/me2me_host_authenticator_factory.h
diff --git a/remoting/protocol/me2me_host_authenticator_factory.h b/remoting/protocol/me2me_host_authenticator_factory.h
index 5cc1beed5e75dc49b53ca6492d2079d849c77b88..18ad8d37b4ad0c3605fc7bc91484f02f64a5b551 100644
--- a/remoting/protocol/me2me_host_authenticator_factory.h
+++ b/remoting/protocol/me2me_host_authenticator_factory.h
@@ -27,13 +27,13 @@ class PairingRegistry;
 class Me2MeHostAuthenticatorFactory : public AuthenticatorFactory {
  public:
   // Create a factory that dispenses shared secret authenticators.
-  static scoped_ptr<AuthenticatorFactory> CreateWithSharedSecret(
+  static scoped_ptr<AuthenticatorFactory> CreateWithPin(
       bool use_service_account,
       const std::string& host_owner,
       const std::string& local_cert,
       scoped_refptr<RsaKeyPair> key_pair,
       const std::string& required_client_domain,
-      const SharedSecretHash& shared_secret_hash,
+      const std::string& pin_hash,
       scoped_refptr<PairingRegistry> pairing_registry);
 
   // Create a factory that dispenses third party authenticators.
@@ -62,8 +62,8 @@ class Me2MeHostAuthenticatorFactory : public AuthenticatorFactory {
   scoped_refptr<RsaKeyPair> key_pair_;
   std::string required_client_domain_;
 
-  // Used only for shared secret host authenticators.
-  SharedSecretHash shared_secret_hash_;
+  // Used only for PIN-based host authenticators.
+  std::string pin_hash_;
 
   // Used only for third party host authenticators.
   scoped_ptr<TokenValidatorFactory> token_validator_factory_;