Modernize Text::replaceWholeText().
Pull request: https://github.com/WebKit/WebKit/pull/356
Pull request: https://github.com/WebKit/WebKit/pull/357
Committed r293237 (249898@main): <https://commits.webkit.org/249898@main> Reviewed commits have been landed. Closing PR #357 and removing active labels.
<rdar://problem/92183950>