This started with the merge of the C stack branch. I'm going to skip it for now to make the bot happy.
See, for example: http://build.webkit.org/results/Apple%20MountainLion%20Debug%20WK1%20(Tests)/r163033%20(12509)/results.html
Created attachment 222608 [details] Patch
Comment on attachment 222608 [details] Patch Clearing flags on attachment: 222608 Committed r163058: <http://trac.webkit.org/changeset/163058>
All reviewed patches have been landed. Closing bug.
Re-opening, as the test was only skipped, not fixed.
Created attachment 289119 [details] Patch
Local testing would indicate that this is no longer a problem. I would recommend re-integrating this test and observing if it is still flakey.
Comment on attachment 289119 [details] Patch Clearing flags on attachment: 289119 Committed r206935: <http://trac.webkit.org/changeset/206935>