Revert "cros_generate_update_payload: kill old style update image generation"

cros_generate_update_payload

 #!/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 generate a Chromium OS update for use by the update engine.
 # If a source .bin is specified, the update is assumed to be a delta update.
 
 # --- BEGIN COMMON.SH BOILERPLATE ---
@@ skipping 229 matching lines @@
   cleanup noexit
 
   if [ "$DELTA" -eq "$FLAGS_TRUE" ]; then
     echo "Done generating delta."
   else
     echo "Done generating new style full update."
   fi
 else
   echo "Generating old-style full update"
 
-  # TODO(zbehan): Remove this branch entirely and disable the cmdline option.
-  echo "This is a deprecated and unused behaviour. It also introduces unwanted"
-  echo "dependency to a third script (mk_memento_images) which has become broken."
-  exit 1
-
   trap cleanup INT TERM EXIT
   DST_KERNEL=$(extract_partition_to_temp_file "$FLAGS_image" 2)
   if [ "$FLAGS_patch_kernel" -eq "$FLAGS_TRUE" ]; then
     patch_kernel "$FLAGS_image" "$DST_KERNEL"
   fi
   DST_ROOT=$(extract_partition_to_temp_file "$FLAGS_image" 3)
 
-#  GENERATOR="${SCRIPTS_DIR}/mk_memento_images.sh"
+  GENERATOR="${SCRIPTS_DIR}/mk_memento_images.sh"
 
   CROS_GENERATE_UPDATE_PAYLOAD_CALLED=1 "$GENERATOR" "$DST_KERNEL" "$DST_ROOT"
   mv "$(dirname "$DST_KERNEL")/update.gz" "$FLAGS_output"
 
   trap - INT TERM EXIT
   cleanup noexit
   echo "Done generating full update."
 fi