Initial patch from Will.

src/platform/init/chromeos_shutdown

 #!/bin/sh
 
 # Copyright (c) 2009 The Chromium OS Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 # Shutdown is best-effort. We don't want to die on errors.
 set +e
 
 # Measure shutdown time. /var/log/metrics is created by chromeos_startup.
@@ skipping 11 matching lines @@
 
 # TODO: swapoff as necessary.
 
 # Kill any that may prevent us from unmounting the stateful partition
 # or the crypto-home and then unmount. These should be all that we need
 # to unmount for a clean shutdown.
 kill_with_open_files_on /mnt/stateful_partition /home/chronos
 
 # Unmount our stateful mount points. If any of these fail we do a best-effort
 # attempt to touch a /var/log file for future inspection.
-/usr/sbin/umount.cryptohome
+/usr/sbin/cryptohome --action=unmount
 if [ $? -ne 0 ] ; then
   mount > /var/log/shutdown_cryptohome_umount_failure
 fi
 
 # join hwclock setting, already in progress.  If the job has already been
 # finished and reaped, we need to suppress error output.  It seems that anything
 # on stderr will make the shutdown appear "unclean" from the POV of upstart.
 (fg ${HWCLOCK} || /bin/true) 2> /dev/null
 
 # Measure shutdown time
@@ skipping 10 matching lines @@
 if [ $? -ne 0 ] ; then
   mount > /mnt/stateful_partition/var/log/shutdown_stateful_umount_failure
   mount > /var/log/shutdown_stateful_umount_failure
 fi
 
 # Just in case something didn't unmount properly above.
 sync
 
 # Ensure that we always claim success.
 exit 0