Created attachment 254227 [details] diff This test has recently failed on Yosemite Debug WK2; the diff is attached. It could be related to http://trac.webkit.org/changeset/185180.
Fails on Yosemite Debug WK1 and WK2. A timing dependent test? http://webkit-test-results.appspot.com/dashboards/flakiness_dashboard.html#showAllRuns=true&showExpectations=true&revision=185177&tests=fast%2Fcanvas%2Fwebgl%2Ftex-image-and-sub-image-2d-with-canvas.html