The graphics item usually asks for the stage size when it is created. Because the stage size was not cached but rather was requested via clientWidth and clientHeight an implicit request for layout was invoked. This impact of this bug was very obvious when the benchmark was running with large fixed size in non adaptive mode. This was taking few seconds for benchmark to show the first animation frame.
Created attachment 265527 [details]
Comment on attachment 265527 [details]
Clearing flags on attachment: 265527
Committed r192455: <http://trac.webkit.org/changeset/192455>
All reviewed patches have been landed. Closing bug.