Add a screen to migrate filesystem encryption from eCryptfs to ext4 crypto.

chrome/browser/chromeos/login/oobe_screen.h

 // Copyright (c) 2016 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_OOBE_SCREEN_H_
 #define CHROME_BROWSER_CHROMEOS_LOGIN_OOBE_SCREEN_H_
 
 #include <string>
 
 namespace chromeos {
@@ skipping 27 matching lines @@
   SCREEN_APP_LAUNCH_SPLASH,
   SCREEN_ARC_KIOSK_SPLASH,
   SCREEN_CONFIRM_PASSWORD,
   SCREEN_FATAL_ERROR,
   SCREEN_OOBE_CONTROLLER_PAIRING,
   SCREEN_OOBE_HOST_PAIRING,
   SCREEN_DEVICE_DISABLED,
   SCREEN_UNRECOVERABLE_CRYPTOHOME_ERROR,
   SCREEN_USER_SELECTION,
   SCREEN_ACTIVE_DIRECTORY_PASSWORD_CHANGE,
+  SCREEN_ENCRYPTION_MIGRATION,
 
   // Special "first screen" that initiates login flow.
   SCREEN_SPECIAL_LOGIN,
   // Special "first screen" that initiates full OOBE flow.
   SCREEN_SPECIAL_OOBE,
   // Special test value that commands not to create any window yet.
   SCREEN_TEST_NO_WINDOW,
 
   SCREEN_UNKNOWN  // This must always be the last element.
 };
 
 // Returns the JS name for the given screen.
 std::string GetOobeScreenName(OobeScreen screen);
 
 // Converts the JS name for the given sreen into a Screen instance.
 OobeScreen GetOobeScreenFromName(const std::string& name);
 
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_LOGIN_OOBE_SCREEN_H_