[cros] update screen re-factoring pt.1

chrome/browser/chromeos/login/update_screen_actor.h

+// 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.
+
+#ifndef CHROME_BROWSER_CHROMEOS_LOGIN_UPDATE_SCREEN_ACTOR_H_
+#define CHROME_BROWSER_CHROMEOS_LOGIN_UPDATE_SCREEN_ACTOR_H_
+#pragma once
+
+namespace chromeos {
+
+class UpdateScreenActor {
+ public:
+  virtual ~UpdateScreenActor() {}
+
+  virtual void Show() = 0;
+  virtual void Hide() = 0;
+  virtual void ShowManualRebootInfo() = 0;
+  virtual void SetProgress(int progress) = 0;
+  virtual void ShowCurtain(bool enable) = 0;
+};
+
+}  // namespace UpdateScreen
+
+#endif  // CHROME_BROWSER_CHROMEOS_LOGIN_UPDATE_SCREEN_ACTOR_H_