Create common script file for workon tools. Planning on using in another CL.

cros_workon

Index: cros_workon
diff --git a/cros_workon b/cros_workon
index 73431a31099ac2bab69925fc9fafc8b71a664880..e9d02426be75dab227e9d604e489af2d3fe01d2d 100755
--- a/cros_workon
+++ b/cros_workon
@@ -14,6 +14,9 @@
 # The path to common.sh should be relative to your script's location.
 . "$(dirname "$0")/common.sh"
 
+# Load common functions for workon scripts.
+. "$(dirname "$0")/lib/cros_workon_common.sh"
+
 # Script must be run inside the chroot
 restart_in_chroot_if_needed $*
 get_default_board
@@ -154,20 +157,6 @@ ebuild_iterate() {
   done
 }
 
-show_workon_ebuilds() {
-  pushd "${BOARD_DIR}"/etc/ 1> /dev/null
-  source make.conf
-  popd 1> /dev/null
-  local CROS_OVERLAYS="${PORTDIR_OVERLAY}"
-
-  for overlay in ${CROS_OVERLAYS}; do
-    pushd ${overlay} 1> /dev/null
-    find . -name '*.ebuild' | xargs fgrep cros-workon | \
-      awk -F / '{ print $2 "/" $3 }' | uniq | sort
-    popd 1> /dev/null
-  done
-}
-
 # --all makes commands operate on different lists
 if [ ${FLAGS_all} = "${FLAGS_TRUE}" ]; then
   case ${WORKON_CMD} in