Add ability to vm library to retry until we can ssh into it.

bin/cros_run_vm_test

 #!/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.
 #
 # Runs a given test case under a VM.
 
 . "$(dirname $0)/../common.sh"
 . "$(dirname $0)/../lib/cros_vm_lib.sh"
 . "$(dirname "$0")/../lib/cros_vm_constants.sh"
 
+MAX_RETRIES=3
+
 DEFINE_string image_path "" "Full path of the VM image"
 DEFINE_string test_case "" "Name of the test case to run"
 
 set -e
 
 # Parse command line.
 FLAGS "$@" || exit 1
 eval set -- "${FLAGS_ARGV}"
 
 # Use latest if not specified.
 if [ -z "${FLAGS_image_path}" ]; then
   LATEST_IMAGE="$(${SCRIPTS_DIR}/get_latest_image.sh)/${DEFAULT_QEMU_IMAGE}"
   info "Using latest vm image ${LATEST_IMAGE}"
   FLAGS_image_path=${LATEST_IMAGE}
 fi
 
 [ -e "${FLAGS_image_path}" ] || die "Image ${FLAGS_image_path} does not exist."
 
 [ -n "${FLAGS_test_case}" ] || die "You must specify a test case."
 
 trap stop_kvm EXIT
 start_kvm "${FLAGS_image_path}"
+info "Checking for ssh access to virtual machine."
+retry_until_ssh ${MAX_RETRIES}
 "$(dirname $0)"/../run_remote_tests.sh \
   --ssh_port=${FLAGS_ssh_port} \
   --remote=127.0.0.1 \
   "${FLAGS_test_case}"