add scroll offset calculation
add scroll offset calculation

Issue: ENYO-527
Enyo-DCO-1.1-Signed-off-by: Ryan Duffy (ryan.duffy@lge.com)

PKRoma/enyo,beni55/enyo,soapdog/enyo,soapdog/enyo,kustomzone/enyo,mcanthony/enyo,mcanthony/enyo,bright-sparks/enyo,kustomzone/enyo,PKRoma/enyo,wikieswan/enyo,bright-sparks/enyo,enyojs/enyo,beni55/enyo,wikieswan/enyo,enyojs/enyo