Added restart_in_chroot_if_needed to common.sh.

src/scripts/common.sh

 # 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.
 
 # Common constants for build scripts
 # This must evaluate properly for both /bin/bash and /bin/sh
 
 # All scripts should die on error unless commands are specifically excepted
 # by prefixing with '!' or surrounded by 'set +e' / 'set -e'.
 # TODO: Re-enable this once shflags is less prone to dying.
@@ skipping 189 matching lines @@
 
   # Rebuild the package
   pushd "$TOP_SCRIPT_DIR"
   rm -f ../${PKG_BASE}_*.deb
   dpkg-buildpackage -b -tc -us -uc -j$NUM_JOBS
   mv ../${PKG_BASE}_*.deb "$OUT_DIR"
   rm ../${PKG_BASE}_*.changes
   popd
 }
 
+# Enter a chroot and restart the current script if needed
+function restart_in_chroot_if_needed {
+  if [ $INSIDE_CHROOT -ne 1 ]
+  then
+    # Equivalent to enter_chroot.sh -- <current command>
+    exec $SCRIPTS_DIR/enter_chroot.sh -- \
+      $CHROOT_TRUNK_DIR/src/scripts/$(basename $0) $*
+  fi
+}
+
 # Fail unless we're inside the chroot.  This guards against messing up your
 # workstation.
 function assert_inside_chroot {
   if [ $INSIDE_CHROOT -ne 1 ]
   then
     echo "This script must be run inside the chroot.  Run this first:"
     echo "    $SCRIPTS_DIR/enter_chroot.sh"
     exit 1
   fi
 }
@@ skipping 125 matching lines @@
   path=${1:?}
   shift
 
   if ! sudo umount -d "${path}"; then
     warn "Failed to unmount ${path}"
     warn "Doing a lazy unmount"
 
     sudo umount -d -l "${path}" || die "Failed to lazily unmount ${path}"
   fi
 }