Remove authenticated_ fields from stubs.

remoting/host/user_authenticator_fake.cc

 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "remoting/host/user_authenticator_fake.h"
 
 #include <string>
 
 namespace remoting {
 
 UserAuthenticatorFake::UserAuthenticatorFake() {}
 UserAuthenticatorFake::~UserAuthenticatorFake() {}
 
 bool UserAuthenticatorFake::Authenticate(const std::string& username,
                                          const std::string& password) {
-  return true;
+  return (username.compare(fail_username()) ||
+      password.compare(fail_password()));
+}
+
+const char* UserAuthenticatorFake::fail_username() {
+  return "userfail";
+}
+
+const char* UserAuthenticatorFake::fail_password() {
+  return "passwordfail";
 }
 
 }  // namespace remoting