Const-ify ProbabilityGrid::ToProto (#238)
Const-ify ProbabilityGrid::ToProto (#238)


wohe/cartographer,wohe/cartographer,cartographer-project/cartographer,googlecartographer/cartographer,wohe/cartographer,larics/cartographer,googlecartographer/cartographer,googlecartographer/cartographer,googlecartographer/cartographer,damonkohler/cartographer,cartographer-project/cartographer,larics/cartographer,damonkohler/cartographer,larics/cartographer,cartographer-project/cartographer,cartographer-project/cartographer,damonkohler/cartographer,larics/cartographer,wohe/cartographer,damonkohler/cartographer