Make more use of smart pointers.
Pull request: https://github.com/WebKit/WebKit/pull/17278
Committed 267528@main (dc328646ce2f): <https://commits.webkit.org/267528@main> Reviewed commits have been landed. Closing PR #17278 and removing active labels.
<rdar://problem/114793209>
*** Bug 261181 has been marked as a duplicate of this bug. ***