The patch for Bug 156133 shows that testRunner.waitUntilDone() is called multiple times when running some of the tests in LayoutTests/accessibility and LayoutTests/animations. While calling waitUntilDone() twice in a row doesn't cause any issues in practice, it prevents the patch in Bug 156133 from landing, which would enforce more correct test behavior (and hopefully prevent flaky tests from landing in the tree in the future).
Created attachment 300131 [details] Patch v1
Comment on attachment 300131 [details] Patch v1 rs=me pending EWS
Comment on attachment 300131 [details] Patch v1 Clearing flags on attachment: 300131 Committed r211573: <http://trac.webkit.org/changeset/211573>
All reviewed patches have been landed. Closing bug.