Revert "Fix race condition in manifest_versions.py."
Revert "Fix race condition in manifest_versions.py."

This reverts commit fdf0c758dd67d4c48898f3d9fdedabdac4b43c63

Suspected of breaking canaries.

BUG=chromium-os:27521
TEST=none

Change-Id: I6ac4741a88fae5d712945f826224ba428187e282
Reviewed-on: https://gerrit.chromium.org/gerrit/17637
Reviewed-by: David James <f231dc574bbeb62604660cbc162d1b8642a0a3af@chromium.org>
Tested-by: David James <f231dc574bbeb62604660cbc162d1b8642a0a3af@chromium.org>

bpsinc-native/src_third_party_chromite,chadversary/chromiumos.chromite,bpsinc-native/src_third_party_chromite,chadversary/chromiumos.chromite,zhang0137/chromite,bpsinc-native/src_third_party_chromite,zhang0137/chromite,coreos/chromite,coreos/chromite,coreos/chromite,zhang0137/chromite