On Mac, don't show menu icons. Native apps don't use them.
On Mac, don't show menu icons. Native apps don't use them.

Change-Id: Iec5a2db8ff1bc1f85a62736fe671d04178f65f60

ghutchis/avogadroapp,wadejong/avogadroapp,wadejong/avogadroapp,wadejong/avogadroapp,ghutchis/avogadroapp,OpenChemistry/avogadroapp,OpenChemistry/avogadroapp,ghutchis/avogadroapp,ghutchis/avogadroapp,OpenChemistry/avogadroapp,OpenChemistry/avogadroapp