Females pass down Hidden Abilities.
Males can pass them down through Ditto.
Genderless Pokemon can pass them down through Ditto.
In Generation VI, any Pokémon, including male and genderless Pokémon, can pass down their Hidden Ability when bred with Ditto. Ditto's Ability is irrelevant to inheritance. If the male is bred with another Pokémon from the same egg group, Hidden Abilities will not be passed down. Source.