Fix build deps. (#5884)
Fix build deps. (#5884)

Co-authored-by: Sarah Heimlich <a808387b43fd7c93f91d4e4e6d52fdc31759df80@google.com>
PolymerLabs/arcs,PolymerLabs/arcs,PolymerLabs/arcs,PolymerLabs/arcs,PolymerLabs/arcs,PolymerLabs/arcs,PolymerLabs/arcs,PolymerLabs/arcs