Turn on --fast on official builds.

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 95 matching lines @@
 # Set up a global ALL_BOARDS value
 if [ -d $SRC_ROOT/overlays ]; then
   ALL_BOARDS=$(cd $SRC_ROOT/overlays;ls -1d overlay-* 2>&-|sed 's,overlay-,,g')
 fi 
 # Strip CR
 ALL_BOARDS=$(echo $ALL_BOARDS)
 # Set a default BOARD
 #DEFAULT_BOARD=x86-generic # or...
 DEFAULT_BOARD=$(echo $ALL_BOARDS | awk '{print $NF}')
 
-# Enable --fast by default on non-official builds
+# Enable --fast by default.
 DEFAULT_FAST="${FLAGS_TRUE}"
-if [ "${CHROMEOS_OFFICIAL:-0}" = "1" ]; then
-  DEFAULT_FAST="${FLAGS_FALSE}"
-fi
 
 # Detect whether we're inside a chroot or not
 if [ -e /etc/debian_chroot ]
 then
   INSIDE_CHROOT=1
 else
   INSIDE_CHROOT=0
 fi
 
 # Directory locations inside the dev chroot
@@ skipping 388 matching lines @@
 chroot_hacks_from_outside() {
   # Give args better names.
   local chroot_dir="${1}"
 
   # Add root as a sudoer if not already done.
   if ! sudo grep -q '^root ALL=(ALL) ALL$' "${chroot_dir}/etc/sudoers" ; then
     info "Upgrading old chroot (pre 2010-10-19) - adding root to sudoers"
     sudo bash -c "echo root ALL=\(ALL\) ALL >> \"${chroot_dir}/etc/sudoers\""
   fi
 }