The gfx/layers/apz/test/mochitest/test_group_touchevents.html test on Windows 8 is permafailing. This job is hidden on integration branches/m-c but is available on try (due to capacity issues). After some investigations (bug 1282638 comment 27 to 32) it looks like the test has a subtest which does a touchstart near the left edge of the screen. This appears to be triggering some windows edge swipe gesture detector code, or something along those lines, which causes the touchstart to not get delivered to Firefox right away. This causes the test to hang since it's a deadlock where the test is waiting for the OS to give it the touch event, and the OS is waiting for more touch events to determine if it's a gesture or not. I tested a fix that just moved the touchstart over to not be so close to the edge and it seemed to work.

Comment on attachment 8802549 [details] Bug 1311406 - Make sure the touchstart event isn't so close to the left edge of the screen, or it triggers Windows 8 edge gesture detection code which hangs the test. https://reviewboard.mozilla.org/r/86936/#review85946

Pushed by kgupta@mozilla.com: https://hg.mozilla.org/integration/autoland/rev/89c6fb80de00 Make sure the touchstart event isn't so close to the left edge of the screen, or it triggers Windows 8 edge gesture detection code which hangs the test. r=botond