Use CheckedPtr more for Node types now that Node subclasses CanMakeCheckedPtr. It is more efficient in the case where we don't need the pointer to get automatically nulled out.
Pull request: https://github.com/WebKit/WebKit/pull/17958
Committed 268215@main (bfdea7f1b0ca): <https://commits.webkit.org/268215@main> Reviewed commits have been landed. Closing PR #17958 and removing active labels.
<rdar://problem/115803439>