export CHROME_VERSION by default
export CHROME_VERSION by default

Change-Id: I788ec487f7c63e71a8a7012c1c7c19c02df103e4

BUG=8786
TEST=eval the script to see it is set right

Review URL: http://codereview.chromium.org/4521003

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