Revert "use Google Sans in button, body, input"
Revert "use Google Sans in button, body, input"

This reverts commit 6d9a4813f9cdd45c65267a2997ef7bf3fd6f8766.

PolymerLabs/arcs,PolymerLabs/arcs,PolymerLabs/arcs,PolymerLabs/arcs,PolymerLabs/arcs,PolymerLabs/arcs,PolymerLabs/arcs,PolymerLabs/arcs