cros: Break BaseScreenHandler into two classes.

chrome/browser/chromeos/login/screens/controller_pairing_screen_view.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_SCREENS_CONTROLLER_PAIRING_SCREEN_VIEW_H_
 #define CHROME_BROWSER_CHROMEOS_LOGIN_SCREENS_CONTROLLER_PAIRING_SCREEN_VIEW_H_
 
 #include <string>
 
 #include "base/macros.h"
+#include "chrome/browser/chromeos/login/oobe_screen.h"
 
 namespace base {
 class DictionaryValue;
 }
 
 namespace content {
 class BrowserContext;
 }
 
 namespace chromeos {
@@ skipping 41 matching lines @@
 class ControllerPairingScreenView {
  public:
   class Delegate {
    public:
     virtual ~Delegate() {}
     virtual void OnViewDestroyed(ControllerPairingScreenView* view) = 0;
     virtual void OnScreenContextChanged(const base::DictionaryValue& diff) = 0;
     virtual void OnUserActed(const std::string& action) = 0;
   };
 
+  constexpr static OobeScreen kScreenId =
+      OobeScreen::SCREEN_OOBE_CONTROLLER_PAIRING;
+
   ControllerPairingScreenView();
   virtual ~ControllerPairingScreenView();
 
   virtual void Show() = 0;
   virtual void Hide() = 0;
   virtual void SetDelegate(Delegate* delegate) = 0;
   virtual void OnContextChanged(const base::DictionaryValue& diff) = 0;
   virtual content::BrowserContext* GetBrowserContext() = 0;
 
  private:
   DISALLOW_COPY_AND_ASSIGN(ControllerPairingScreenView);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_LOGIN_SCREENS_CONTROLLER_PAIRING_SCREEN_VIEW_H_