It would fail on win32 when these modules are not present.

BUG=75902
TEST=none

R=mhm@chromium.org

Review URL: http://codereview.chromium.org/6683028

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@77947 0039d316-1c4b-4281-b951-d872f2087c98