mount_helper: drop unused module

There should be no more users of this after devmode-test converted
to chromite, so drop it!

BUG=chromium:1000719
TEST=CQ passes

Change-Id: I3867761accdc1a67a67cf4f900df37e65dbc2568
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crostestutils/+/1808026
Reviewed-by: Achuith Bhandarkar <achuith@chromium.org>
Tested-by: Mike Frysinger <vapier@chromium.org>
Commit-Queue: Mike Frysinger <vapier@chromium.org>
diff --git a/lib/mount_helper.py b/lib/mount_helper.py
deleted file mode 100644
index 2545f8c..0000000
--- a/lib/mount_helper.py
+++ /dev/null
@@ -1,32 +0,0 @@
-# -*- coding: utf-8 -*-
-# Copyright (c) 2013 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.
-
-"""Module containing helper methods for mounting and unmounting an image."""
-
-import os
-
-import constants
-from chromite.lib import cros_build_lib
-
-def MountImage(image_path, root_dir, stateful_dir, read_only, safe=False):
-  """Mounts a Chromium OS image onto mount dir points."""
-  from_dir, image = os.path.split(image_path)
-  cmd = ['./mount_gpt_image.sh',
-         '--from=%s' % from_dir,
-         '--image=%s' % image,
-         '--rootfs_mountpt=%s' % root_dir,
-         '--stateful_mountpt=%s' % stateful_dir]
-  if read_only: cmd.append('--read_only')
-  if safe: cmd.append('--safe')
-  cros_build_lib.RunCommand(
-      cmd, print_cmd=False, cwd=constants.CROSUTILS_DIR, capture_output=True)
-
-
-def UnmountImage(root_dir, stateful_dir):
-  """Unmounts a Chromium OS image specified by mount dir points."""
-  cmd = ['./mount_gpt_image.sh', '--unmount', '--rootfs_mountpt=%s' % root_dir,
-         '--stateful_mountpt=%s' % stateful_dir]
-  cros_build_lib.RunCommand(
-      cmd, print_cmd=False, cwd=constants.CROSUTILS_DIR, capture_output=True)