void SetNonFastScrollableRegion(const Region& non_fast_scrollable_region);
const Region& non_fast_scrollable_region() const {
return non_fast_scrollable_region_;
void SetNonFastScrollableRegion(const Region& non_fast_scrollable_region);
const Region& non_fast_scrollable_region() const {
return non_fast_scrollable_region_;