Use dump-as-markup.js in editing/style/preserve-selection-direction.html instead of manually asserting offsets, etc...
Pull request: https://github.com/WebKit/WebKit/pull/6601
Committed 256819@main (1d5185c742f1): <https://commits.webkit.org/256819@main> Reviewed commits have been landed. Closing PR #6601 and removing active labels.
<rdar://problem/102498609>