Import make_chroot from chromiumos-overlay.
Import make_chroot from chromiumos-overlay.

Imported as of 09d3117c483c60f55f552694b84b0964dfc17477.

Only modification is so that it can find common.sh.

BUG=chromium-os:25697
TEST=None

Change-Id: Idb43f1ecff3dff10a61396629a344c8bd10f505e
Reviewed-on: https://gerrit.chromium.org/gerrit/15317
Tested-by: Brian Harring <fdc2d0a2e2340b623587cee5ea8dff425d1eb1f3@chromium.org>
Reviewed-by: David James <f231dc574bbeb62604660cbc162d1b8642a0a3af@chromium.org>
Reviewed-by: Mike Frysinger <8f3f75c74bd5184edcfa6534cab3c13a00a2f794@chromium.org>
Commit-Ready: Brian Harring <fdc2d0a2e2340b623587cee5ea8dff425d1eb1f3@chromium.org>

smilart/scripts,mjg59/scripts,mjg59/scripts,crawford/scripts,endocode/scripts,nicescale/scripts,trnubo/scripts,gtank/scripts,bcwaldon/coreos-scripts,vmware/coreos-scripts,glevand/coreos--scripts,BugRoger/scripts,mischief/scripts,crawford/scripts,zhang0137/scripts,trnubo/scripts,coreos/scripts,BugRoger/scripts,glevand/coreos--scripts,gtank/scripts,nicescale/scripts,gtank/scripts,zhang0137/scripts,endocode/scripts,smilart/scripts,andrejro/coreos--scripts,fivethreeo/scripts,bcwaldon/coreos-scripts,fivethreeo/scripts,crawford/scripts,andrejro/coreos--scripts,smilart/scripts,zhang0137/scripts,sigma/coreos-scripts,bcwaldon/coreos-scripts,coreos/scripts,mjg59/scripts,marineam/coreos-scripts,andrejro/coreos--scripts,sigma/coreos-scripts,BugRoger/scripts,vmware/coreos-scripts,trnubo/scripts,nicescale/scripts,sigma/coreos-scripts,vmware/coreos-scripts,marineam/coreos-scripts,mischief/scripts,mischief/scripts,fivethreeo/scripts,marineam/coreos-scripts,endocode/scripts