This test was added at http://trac.webkit.org/changeset/141616 and it has been consistently timed out on Win7 bot http://test-results.appspot.com/dashboards/flakiness_dashboard.html#group=@ToT - chromium.org&tests=fast/css-grid-layout/grid-preferred-logical-widths.html
Marked http://trac.webkit.org/changeset/141726
Probably related to bug 106378 (more Grid tests failing on Windows).