cros: Enable Ext4 migration in ARC kiosk mode.

chrome/browser/chromeos/login/arc_kiosk_controller.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_ARC_KIOSK_CONTROLLER_H_
 #define CHROME_BROWSER_CHROMEOS_LOGIN_ARC_KIOSK_CONTROLLER_H_
 
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
 #include "chrome/browser/chromeos/app_mode/arc/arc_kiosk_app_service.h"
@@ skipping 32 matching lines @@
  private:
   void CleanUp();
   void CloseSplashScreen();
 
   // LoginPerformer::Delegate implementation:
   void OnAuthFailure(const AuthFailure& error) override;
   void OnAuthSuccess(const UserContext& user_context) override;
   void WhiteListCheckFailed(const std::string& email) override;
   void PolicyLoadFailed() override;
   void SetAuthFlowOffline(bool offline) override;
+  void OnOldEncryptionDetected(const UserContext& user_context,
+                               bool has_incomplete_migration) override;
 
   // UserSessionManagerDelegate implementation:
   void OnProfilePrepared(Profile* profile, bool browser_launched) override;
 
   // ArcKioskAppService::Delegate implementation:
   void OnAppStarted() override;
   void OnAppWindowLaunched() override;
 
   // ArcKioskSplashScreenView::Delegate implementation:
   void OnCancelArcKioskLaunch() override;
@@ skipping 12 matching lines @@
   base::OneShotTimer splash_wait_timer_;
   bool launched_ = false;
   base::WeakPtrFactory<ArcKioskController> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(ArcKioskController);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_LOGIN_ARC_KIOSK_CONTROLLER_H_