Fix 'except' and 'prefer' spelling.

build/install-chroot.sh

 #!/bin/bash -e
 
 # Copyright (c) 2012 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 # This script installs Debian-derived distributions in a chroot environment.
 # It can for example be used to have an accurate 32bit build and test
 # environment when otherwise working on a 64bit machine.
 # N. B. it is unlikely that this script will ever work on anything other than a
 # Debian-derived system.
 
 # Older Debian based systems had both "admin" and "adm" groups, with "admin"
 # apparently being used in more places. Newer distributions have standardized
-# on just the "adm" group. Check /etc/group for the prefered name of the
+# on just the "adm" group. Check /etc/group for the preferred name of the
 # administrator group.
 admin=$(grep '^admin:' /etc/group >&/dev/null && echo admin || echo adm)
 
 usage() {
   echo "usage: ${0##*/} [-m mirror] [-g group,...] [-s] [-c]"
   echo "-b dir       additional directories that should be bind mounted,"
   echo '             or "NONE".'
   echo "             Default: if local filesystems present, ask user for help"
   echo "-g group,... groups that can use the chroot unauthenticated"
   echo "             Default: '${admin}' and current user's group ('$(id -gn)')"
@@ skipping 817 matching lines @@
 
 For Chrome, this probably means you want to make your "out" directory a
 symbolic link that points somewhere inside of "${HOME}/chroot".
 
 You still need to run "gclient runhooks" whenever you switch from building
 outside of the chroot to inside of the chroot. But you will find that you
 don't have to repeatedly erase and then completely rebuild all your object
 and binary files.
 
 EOF