Adds ebuild support to build_autotest
Adds ebuild support to build_autotest

Review URL: http://codereview.chromium.org/604013

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