enter chroot: permit chrome_root to contain symlink
enter chroot: permit chrome_root to contain symlink

Review URL: http://codereview.chromium.org/596108

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