An experimental code in platform/graphics/mac/controls/ControlMac.mm went unintentionally in 258794@main.
<rdar://problem/104140855>
Pull request: https://github.com/WebKit/WebKit/pull/8544
Committed 258806@main (8cd17f9b7883): <https://commits.webkit.org/258806@main> Reviewed commits have been landed. Closing PR #8544 and removing active labels.