Tests in fast/shapes/shape-outside-floats directory are very flaky, often having incorrect layout. See for example:
Complete history: <http://webkit-test-results.appspot.com/dashboards/flakiness_dashboard.html#showAllRuns=true&tests=fast%2Fshapes%2Fshape-outside-floats%2F>.
It looks to me like these aren't flaky anymore. (There are some failures on EFL and GTK, but those are tracked in different bugs)
Indeed, thanks for checking!