This is in preparation for vertical-writing mode support for RenderFileUploadControl.
<rdar://problem/116356078>
Pull request: https://github.com/WebKit/WebKit/pull/18504
Committed 268752@main (a073a3d3be8b): <https://commits.webkit.org/268752@main> Reviewed commits have been landed. Closing PR #18504 and removing active labels.