message: Change from DCHECK to CHECK.
diff: @@ -63,7 +63,7 @@ class RayCaster {
  }
  bool nextRayIndex(AnyIndex* ray_index) {
  - DCHECK_NOTNULL(ray_index);
  + CHECK_NOTNULL(ray_index);
  *ray_index = curr_index_;
  bool not_at_end = curr_index_ != end_index_;
  