compositing/columns/composited-rl-paginated-repaint.html became flaky on March 22nd (first failure was around r166116, but the culprit could easily be 20-30 revisions earlier).
Diff shows a missing repaint:
@@ -10,9 +10,6 @@
(position 4.00 131.00)
(bounds 130.00 130.00)
- (repaint rects
- (rect 27.00 25.00 52.00 77.00)
Marked as flaky in <http://trac.webkit.org/r166472>.
Perhaps r166117 (Don't flush compositing layers within FrameView::willPaintContents())?
*** This bug has been marked as a duplicate of bug 128255 ***