svg/custom/svg-fonts-without-missing-glyph.xhtml has become flaky recently, possibly due to enabling kerning and ligatures. When it fails, text box widths are different. https://webkit-test-results.appspot.com/dashboards/flakiness_dashboard.html#showAllRuns=true&tests=svg%2Fcustom%2Fsvg-fonts-without-missing-glyph.xhtml
*** Bug 140583 has been marked as a duplicate of this bug. ***
http://trac.webkit.org/changeset/178573 did not fix it.