cros: Mount the existing eCryptfs vault to start migration.

chromeos/cryptohome/homedir_methods.h

Index: chromeos/cryptohome/homedir_methods.h
diff --git a/chromeos/cryptohome/homedir_methods.h b/chromeos/cryptohome/homedir_methods.h
index fdd3e6308e1ba4d37ebdb12e300170468a021202..c89b8eac6bff0234f6c9875d471ea5e2dcafe294 100644
--- a/chromeos/cryptohome/homedir_methods.h
+++ b/chromeos/cryptohome/homedir_methods.h
@@ -107,9 +107,8 @@ class CHROMEOS_EXPORT HomedirMethods {
       const GetAccountDiskUsageCallback& callback) = 0;
 
   // Asks cryptohomed to migrate the cryptohome to the new encryption method
-  // for the user specified by |id|, using |auth| to unlock the key.
+  // for the user specified by |id|.
   virtual void MigrateToDircrypto(const Identification& id,
-                                  const Authorization& auth,
                                   const DBusResultCallback& callback) = 0;
 
   // Creates the global HomedirMethods instance.