Move UserContext to its own file

chrome/browser/chromeos/login/ui/login_display.h

 // Copyright 2014 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.
 
 #ifndef CHROME_BROWSER_CHROMEOS_LOGIN_UI_LOGIN_DISPLAY_H_
 #define CHROME_BROWSER_CHROMEOS_LOGIN_UI_LOGIN_DISPLAY_H_
 
 #include <string>
 #include <vector>
 
 #include "base/callback.h"
 #include "base/strings/string16.h"
 #include "chrome/browser/chromeos/login/help_app_launcher.h"
 #include "chrome/browser/chromeos/login/users/remove_user_delegate.h"
 #include "chrome/browser/chromeos/login/users/user.h"
 #include "chrome/browser/chromeos/login/users/user_manager.h"
 #include "ui/gfx/image/image.h"
 #include "ui/gfx/native_widget_types.h"
 #include "ui/gfx/rect.h"
 
 namespace chromeos {
 
+class UserContext;
+
 // TODO(nkostylev): Extract interface, create a BaseLoginDisplay class.
 // An abstract class that defines login UI implementation.
 class LoginDisplay : public RemoveUserDelegate {
  public:
   // Supported authentication types for login.
   enum AuthType {
     // Authenticates using the user's regular password.
     OFFLINE_PASSWORD,
 
     // Authenticates by forced online GAIA sign in.
@@ skipping 198 matching lines @@
   // in redesigned login stack.
   // Login stack (and this object) will be recreated for next user sign in.
   bool is_signin_completed_;
 
   DISALLOW_COPY_AND_ASSIGN(LoginDisplay);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_LOGIN_UI_LOGIN_DISPLAY_H_