Added a function to update chroot sudoers automatically.

enter_chroot.sh

 #!/bin/bash
 
 # 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.
 
 # Script to enter the chroot environment
 
 # Load common constants.  This should be the first executable line.
 # The path to common.sh should be relative to your script's location.
@@ skipping 236 matching lines @@
   info "or you'll end up deleting $FLAGS_trunk too!"
   exit 0
 fi
 
 if [ $FLAGS_unmount -eq $FLAGS_TRUE ]
 then
   teardown_env
   exit 0
 fi
 
+# Apply any hacks needed to update the chroot.
+chroot_hacks_from_outside "${FLAGS_chroot}"
+
+
 # Make sure we unmount before exiting
 trap teardown_env EXIT
 setup_env
 
 # Get the git revision to pass into the chroot.
 #
 # This must be determined outside the chroot because (1) there is no
 # git inside the chroot, and (2) if there were it would likely be
 # the wrong version, which would mess up the .git directories.
 #
@@ skipping 27 matching lines @@
 # Run command or interactive shell.  Also include the non-chrooted path to
 # the source trunk for scripts that may need to print it (e.g.
 # build_image.sh).
 sudo chroot "$FLAGS_chroot" sudo -i -u $USER $CHROOT_PASSTHRU \
   EXTERNAL_TRUNK_PATH="${FLAGS_trunk}" LANG=C SSH_AGENT_PID="${SSH_AGENT_PID}" \
   SSH_AUTH_SOCK="${SSH_AUTH_SOCK}" -- "$@"
 
 # Remove trap and explicitly unmount
 trap - EXIT
 teardown_env