Summary: @public The new CSSLayout have a wrong calculate for the getRelativePosition. So use the getLeadingPosition will get 0 instead of return undefined. Fix it with using isLeadingPosDefined.
Reviewed By: fkgozali
Differential Revision: D3640799
fbshipit-source-id: 50d3bd2ea4c0d8bf96ba34297425ba269b0535cd