The following layout test is flaky on GTK+. It fails very ocasionally.
When it does the diff is the following: https://build.webkit.org/results/GTK%20Linux%2064-bit%20Release%20%28Tests%29/r183725%20%288220%29/fast/inline/layout-after-inserting-nested-br-diffs.html
[insert probable cause]
The test(s) filed under this bug have been consistently passing for the last 4000 revisions. Marking bug as fixed.
Committed r263254: <https://trac.webkit.org/changeset/263254>