Don't build_autotests separately

sync_build_test.sh

 #!/bin/bash
 
 # Copyright (c) 2010 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 sync your checkout, build a Chromium OS image, and test it all
 # with one command.  Can also check out a new Chromium OS checkout and
 # perform a subset of the above operations.
 #
@@ skipping 171 matching lines @@
     fi
     if [[ -z "${FLAGS_remote}" ]]; then
       echo "Please specify --remote with --image_to_live"
       exit 1
     fi
   fi
 
   if [[ ${FLAGS_mod_image_for_test} -eq ${FLAGS_TRUE} ]]; then
     # Override any specified chronos password with the test one
     FLAGS_chronos_passwd="test0000"
-    # Default to building autotests whenever we mod image for test.
-    FLAGS_build_autotest=${FLAGS_TRUE}
     # If you're modding for test, you also want developer packages.
     FLAGS_withdev=${FLAGS_TRUE}
   fi
 
   if [[ -n "${FLAGS_image_to_usb}" ]]; then
     local device=${FLAGS_image_to_usb#/dev/}
     if [[ -z "${device}" ]]; then
       echo "Expected --image_to_usb option of /dev/* format"
       exit 1
     fi
@@ skipping 384 matching lines @@
   fi
 
   trap - EXIT
   echo "Successfully used ${FLAGS_top} to:"
   describe_steps
   show_duration
 }
 
 
 main $@