`region_attr.needs_remset_update()` is used to cache the corresponding remset `is_tracked()` state. One can rename the method to make the relation more explicit.

Before:

```
_region_attr.set_has_remset(r->hrm_index(), r->rem_set()->is_tracked());
...
assert(region_attr.needs_remset_update() == hr_obj->rem_set()->is_tracked(),
```

After:

```
_region_attr.set_remset_is_tracked(r->hrm_index(), r->rem_set()->is_tracked());
...
assert(region_attr.remset_is_tracked() == hr_obj->rem_set()->is_tracked(),
```

A more subtle reason is that `is_tracked()` tells the current remset state, and whether remset needs to be updated or not is sth the caller decides. In `G1ParScanThreadState::write_ref_field_post`, all four checks are trying to decide if a card should be enqueued (or equivalently if the remset should be updated).

```
if (HeapRegion::is_in_same_region(p, obj)) {
  ...
if (from_attr.is_new_survivor()) {
  ...
if (dest_attr.is_in_cset()) {
  ...
if (!region_attr.needs_remset_update()) { <--- check the remset state, and the caller decides whether remset needs to be updated or not.
  ...
```