Adds ebuild support to build_autotest

src/scripts/build_autotest.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.
 
 # This script makes autotest client tests inside an Ubuntu chroot
 # environment.  The idea is to compile any platform-dependent autotest
 # client tests in the build environment, since client systems under
 # test lack the proper toolchain.
 #
 # The user can later run autotest against an ssh enabled test client system, or
 # install the compiled client tests directly onto the rootfs image, using
 # mod_image_for_test.sh.
 
 . "$(dirname "$0")/common.sh"
 . "$(dirname "$0")/autotest_lib.sh"
 
 # Script must be run inside the chroot
 assert_inside_chroot
 
 DEFAULT_CONTROL=client/site_tests/setup/control
 
 DEFINE_string control "${DEFAULT_CONTROL}" \
   "Setup control file -- path relative to the destination autotest directory" c
+DEFINE_string board "" \
+  "Board name for the target you are building if using portage build system"
 
 # More useful help
 FLAGS_HELP="usage: $0 [flags]"
 
 # parse the command-line
 FLAGS "$@" || exit 1
 eval set -- "${FLAGS_ARGV}"
 set -e
 
 AUTOTEST_SRC="${GCLIENT_ROOT}/src/third_party/autotest/files"
 # Destination in chroot to install autotest.
 AUTOTEST_DEST="/usr/local/autotest"
 
+# If new build system flag passed, use ebuild and exit
+if [ -n "${FLAGS_board}" ]; then
+  sudo GCLIENT_ROOT="${GCLIENT_ROOT}" FLAGS_control=${FLAGS_control} \
+    "emerge-${FLAGS_board}" -a chromeos-base/autotest
+  exit 0
+fi
+
 # Copy a local "installation" of autotest into the chroot, to avoid
 # polluting the src dir with tmp files, results, etc.
 update_chroot_autotest "${CHROOT_TRUNK_DIR}/src/third_party/autotest/files" \
   "${AUTOTEST_DEST}"
 
 # Create python package init files for top level test case dirs.
 function touchInitPy() {
   local dirs=${1}
   for base_dir in $dirs
   do
     local sub_dirs="$(find ${base_dir} -maxdepth 1 -type d)"
     for sub_dir in ${sub_dirs}
     do
       touch ${sub_dir}/__init__.py
     done
   touch ${base_dir}/__init__.py
   done
 }
 
 cd ${AUTOTEST_DEST}
 touchInitPy client/tests client/site_tests
 touch __init__.py
 
 # Export GCLIENT_ROOT so that tests have access to the source and build trees
 export GCLIENT_ROOT
 
 # run the magic test setup script.
 echo "Building tests using ${FLAGS_control}..."
 client/bin/autotest ${FLAGS_control}