glyphs and sprite offline

[chikashimiyama]

Hi I'm trying to load glyphs and sprite from local storage. My debugger and console posts no complain but the map isn't displayed at all. if I use URL like "https://rawgit.com/lukasmartinelli/osm-liberty/gh-pages/sprites/osm-liberty". it works perfectly.
Would it be not possible to load glyphs and sprite from the local storage?

I tested it on iPad.