vold: Add an optional wipe paramter to the volume format command

The new wipe option to the vold format command will invoke BLKDISCARD
on the partition before invoking newfs_msdos.  This will be used whenever
a full wipe of the device is wanted, as this is more secure than just
doing newfs_msdos.

Bug: 9392982
Change-Id: Ie106f1b9cc70abc61206006d1821641c27c7ccae
diff --git a/VoldUtil.h b/VoldUtil.h
index 30a3add..469489a 100644
--- a/VoldUtil.h
+++ b/VoldUtil.h
@@ -17,6 +17,12 @@
 #ifndef _VOLDUTIL_H
 #define _VOLDUTIL_H
 
+#include <sys/cdefs.h>
+
 #define ARRAY_SIZE(a) (sizeof(a) / sizeof(*(a)))
 
+__BEGIN_DECLS
+  unsigned int get_blkdev_size(int fd);
+__END_DECLS
+
 #endif