REGRESSION(r239175): Styles sidebar unexpectedly collapses after toggling a property Steps to Reproduce: 1. Inspect <http://apple.com> 2. Inspect the "Trade in your current iPhone" or some page text near the top of the screen 3. In the Styles sidebar toggle "margin: auto" a few times => Styles sidebar unexpectedly collapses Notes: - Regressed in https://trac.webkit.org/changeset/239175/webkit
<rdar://problem/46824067>
I can no longer reproduce this, but wasn't able to locate the progression by bisecting. It was probably resolved by either <https://webkit.org/b/192783> or <https://webkit.org/b/192871>.