arc: Add splash screen for ARC++ Kiosk startup

chrome/browser/chromeos/login/screens/arc_kiosk_splash_screen_actor.h

+// Copyright 2017 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_SCREENS_ARC_KIOSK_SPLASH_SCREEN_ACTOR_H_
+#define CHROME_BROWSER_CHROMEOS_LOGIN_SCREENS_ARC_KIOSK_SPLASH_SCREEN_ACTOR_H_
+
+namespace chromeos {
+
+// Interface for UI implemenations of the ArcKioskSplashScreen.
+class ArcKioskSplashScreenActor {
+ public:
+  enum ArcKioskState {
+    ARC_KIOSK_STATE_STARTING_SESSION,
+    ARC_KIOSK_STATE_WAITING_APP_LAUNCH,
+    ARC_KIOSK_STATE_WAITING_APP_WINDOW,
+  };
+
+  class Delegate {
+   public:
+    // Invoked when the launch bailout shortcut key is pressed.
+    virtual void OnCancelArcKioskLaunch() = 0;
+
+   protected:
+    virtual ~Delegate() = default;
+  };
+
+  virtual ~ArcKioskSplashScreenActor() = default;
+
+  // Shows the contents of the screen.
+  virtual void Show() = 0;
+
+  // Set the current ARC kiosk state.
+  virtual void UpdateArcKioskState(ArcKioskState state) = 0;
+
+  // Sets screen this actor belongs to.
+  virtual void SetDelegate(Delegate* delegate) = 0;
+};
+
+}  // namespace chromeos
+
+#endif  // CHROME_BROWSER_CHROMEOS_LOGIN_SCREENS_ARC_KIOSK_SPLASH_SCREEN_ACTOR_H_