Code review comment for lp:~mhr3/unity/pass-extra-hints-for-perform-action

LGTM

Only comment is that it would be better if you could use the Hints typedef in dash::Preview::PerformAction.

161 + void PerformAction(std::string const& id,
162 + std::map<std::string, glib::Variant> const& hints =
163 + std::map<std::string, glib::Variant>()) const;