Consistent creation/destruction of user data.

Preparing and destroying users currently needs to be split across
installd, system_server, and vold, since no single party has all the
required SELinux permissions.

Bug: 27896918, 25861755
Change-Id: Ieec14ccacfc7a3a5ab00df47ace7318feb900c38
diff --git a/Ext4Crypt.h b/Ext4Crypt.h
index dff2953..89cfbab 100644
--- a/Ext4Crypt.h
+++ b/Ext4Crypt.h
@@ -35,5 +35,6 @@
 bool e4crypt_lock_user_key(userid_t user_id);
 
 bool e4crypt_prepare_user_storage(const char* volume_uuid, userid_t user_id, int serial, int flags);
+bool e4crypt_destroy_user_storage(const char* volume_uuid, userid_t user_id, int flags);
 
 __END_DECLS