cros: Break BaseScreenHandler into two classes.

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

 // Copyright 2013 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_APP_LAUNCH_SPLASH_SCREEN_VIEW_H_
 #define CHROME_BROWSER_CHROMEOS_LOGIN_SCREENS_APP_LAUNCH_SPLASH_SCREEN_VIEW_H_
 
 #include "base/strings/string16.h"
+#include "chrome/browser/chromeos/login/oobe_screen.h"
 
 namespace chromeos {
 
 // Interface for UI implemenations of the ApplaunchSplashScreen.
 class AppLaunchSplashScreenView {
  public:
   enum AppLaunchState {
     APP_LAUNCH_STATE_LOADING_AUTH_FILE,
     APP_LAUNCH_STATE_LOADING_TOKEN_SERVICE,
     APP_LAUNCH_STATE_PREPARING_NETWORK,
@@ skipping 15 matching lines @@
     virtual void OnNetworkConfigRequested(bool requested) = 0;
 
     // Invoked when network state is changed. |online| is true if the device
     // is connected to the Internet.
     virtual void OnNetworkStateChanged(bool online) = 0;
 
    protected:
     virtual ~Delegate() {}
   };
 
+  constexpr static OobeScreen kScreenId = OobeScreen::SCREEN_APP_LAUNCH_SPLASH;
+
   virtual ~AppLaunchSplashScreenView() {}
 
   // Sets screen this view belongs to.
   virtual void SetDelegate(Delegate* screen) = 0;
 
   // Shows the contents of the screen.
   virtual void Show(const std::string& app_id) = 0;
 
   // Hides the contents of the screen.
   virtual void Hide() = 0;
 
   // Set the current app launch state.
   virtual void UpdateAppLaunchState(AppLaunchState state) = 0;
 
   // Sets whether configure network control is visible.
   virtual void ToggleNetworkConfig(bool visible) = 0;
 
   // Shows the network error and configure UI.
   virtual void ShowNetworkConfigureUI() = 0;
 
   // Returns true if the default network has Internet access.
   virtual bool IsNetworkReady() = 0;
 };
 
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_LOGIN_SCREENS_APP_LAUNCH_SPLASH_SCREEN_VIEW_H_