cros: Show dircryto migration banner

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

Index: chrome/browser/chromeos/login/screens/user_selection_screen.h
diff --git a/chrome/browser/chromeos/login/screens/user_selection_screen.h b/chrome/browser/chromeos/login/screens/user_selection_screen.h
index 26eb81c9d85b8304976f01e02db8fffef8f31414..6ca995808b250c85f8d8cbe8b120be06f25672a6 100644
--- a/chrome/browser/chromeos/login/screens/user_selection_screen.h
+++ b/chrome/browser/chromeos/login/screens/user_selection_screen.h
@@ -123,6 +123,8 @@ class UserSelectionScreen
       public_session_recommended_locales_;
 
  private:
+  class DircryptoMigrationChecker;
+
   EasyUnlockService* GetEasyUnlockServiceForUser(
       const AccountId& account_id) const;
 
@@ -152,6 +154,9 @@ class UserSelectionScreen
   // Token handler util for checking user OAuth token status.
   std::unique_ptr<TokenHandleUtil> token_handle_util_;
 
+  // Helper to check whether a user needs dircrypto migration.
+  std::unique_ptr<DircryptoMigrationChecker> dircrypto_migration_checker_;
+
   base::WeakPtrFactory<UserSelectionScreen> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(UserSelectionScreen);