It stays resident, so try to tidy up, otherwise removing the old
directory will fail.

TBR=maruel@chromium.org
BUG=323300

Review URL: https://codereview.chromium.org/140883005

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@245324 0039d316-1c4b-4281-b951-d872f2087c98