Add logs for update_engine and image_to_live to test artifacts.

bin/cros_run_vm_update

 #!/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.
 #
 # Updates an existing vm image with another image.
 
 # --- BEGIN COMMON.SH BOILERPLATE ---
 # Load common CrOS utilities.  Inside the chroot this file is installed in
@@ skipping 18 matching lines @@
 
 . "${SCRIPT_ROOT}/lib/cros_vm_lib.sh" || die "Unable to load cros_vm_lib.sh"
 
 DEFINE_string payload "" "Full name of the payload to update with."
 DEFINE_string proxy_port "" \
   "Have the client request from this proxy instead of devserver."
 DEFINE_string src_image "" \
   "Create a delta update by passing in the image on the remote machine."
 DEFINE_string stateful_update_flag "" "Flags to pass to stateful update." s
 DEFINE_string image "" "Path of the image to update to." u
+DEFINE_string update_log "update_engine.log" \
+  "Path to log for the update_engine."
 DEFINE_string update_url "" "Full url of an update image."
 DEFINE_string vm_image_path "" "Path of the VM image to update from." v
 
 set -e
 
 # Parse command line.
 FLAGS "$@" || exit 1
 eval set -- "${FLAGS_ARGV}"
 
 [ -n "${FLAGS_vm_image_path}" ] || \
@@ skipping 14 matching lines @@
 if [ -n "${FLAGS_proxy_port}" ]; then
   IMAGE_ARGS="${IMAGE_ARGS} --proxy_port=${FLAGS_proxy_port}"
 fi
 
 "${SCRIPTS_DIR}/image_to_live.sh" \
   --for_vm \
   --remote=127.0.0.1 \
   --ssh_port=${FLAGS_ssh_port} \
   --stateful_update_flag=${FLAGS_stateful_update_flag} \
   --src_image="${FLAGS_src_image}" \
+  --update_log="${FLAGS_update_log}" \
   --update_url="${FLAGS_update_url}" \
   --verify \
   ${IMAGE_ARGS}