The following layout test is flaky on Mac:
Strange that the diff is pixel noise, but it's not happening every time.
Marked as flaky in r157886.
Should this test be in `LayoutTests/compositiong/regions` or in `LayoutTests/fast/regions`?
(In reply to comment #2)
> Should this test be in `LayoutTests/compositiong/regions` or in `LayoutTests/fast/regions`?
The layout tests are being run on the testing bots using virtual machines. Only the tests located in LayoutTests/compositing are guaranteed to be run in an environment that supports accelerated compositing.