Filed by: nerli [at] mozilla.com https://treeherder.mozilla.org/logviewer.html#?job_id=184786093&repo=mozilla-central https://queue.taskcluster.net/v1/task/XWlSj0TgT9aIsXm8IdFDPA/runs/0/artifacts/public/logs/live_backing.log 20:41:23 INFO - 135 INFO TEST-PASS | dom/animation/test/mozilla/test_restyles.html | Visibility animation running on the main-thread on in-view element should not be throttled 20:41:23 INFO - 136 INFO AddTask.js | Leaving test restyling_visibility_animations_on_in_view_element 20:41:23 INFO - 137 INFO AddTask.js | Entering test restyling_outline_offset_animations_on_invisible_element 20:41:23 INFO - Buffered messages finished 20:41:23 ERROR - 138 INFO TEST-UNEXPECTED-FAIL | dom/animation/test/mozilla/test_restyles.html | Outline offset animation running on the main-thread on invisible element should be throttled - got 1, expected +0 20:41:23 INFO - SimpleTest.is@SimpleTest/SimpleTest.js:312:5 20:41:23 INFO - restyling_outline_offset_animations_on_invisible_element@dom/animation/test/mozilla/file_restyles.html:1753:5 20:41:23 INFO - async*add_task/</<@SimpleTest/AddTask.js:57:34 20:41:23 INFO - async*add_task/<@SimpleTest/AddTask.js:31:10 20:41:23 INFO - setTimeout handler*add_task@SimpleTest/AddTask.js:30:7 20:41:23 INFO - @dom/animation/test/mozilla/file_restyles.html:152:3 20:41:23 INFO - waitForPaints@SimpleTest/paint_listener.js:77:5 20:41:23 INFO - waitForPaints/<@SimpleTest/paint_listener.js:65:22 20:41:23 INFO - setTimeout handler*paintListener@SimpleTest/paint_listener.js:32:7 20:41:23 INFO - EventListener.handleEvent*@SimpleTest/paint_listener.js:35:3 20:41:23 INFO - @SimpleTest/paint_listener.js:1:2

Huh, so this failure also happens on non-Android platforms.

Windows ccov is another very slow platform, like Android.

Thanks! That's a quite useful information. Now I think I know the failure reason. We presumably unthrottle the animations there since the test cases take sometimes over 200ms.

The test actually took long but not over 200ms. But still we observed one styles. https://treeherder.mozilla.org/#/jobs?repo=try&revision=7b2783985dce1eec657bed31be83544307de0371&selectedJob=184912379

I came up with an idea to avoid this kind of failures. The idea is just setting 'overflow: hidden' style for body element. This should work. https://treeherder.mozilla.org/#/jobs?repo=try&revision=e2c6aaf003f8d3a09876732af5d97bf9d2bc1284

I should have tried without --artifact. https://treeherder.mozilla.org/#/jobs?repo=try&revision=4cf70ceda990e091ac9fdbf75bcc2dc555988a6b

Comment on attachment 8988086 [details] Bug 1471106 - Set overflow:hidden to body element to avoid accidentally unthrottling animations to update the overflow region. https://reviewboard.mozilla.org/r/253354/#review260252

Pushed by hikezoe@mozilla.com: https://hg.mozilla.org/integration/autoland/rev/7ce13e62bc0e Set overflow:hidden to body element to avoid accidentally unthrottling animations to update the overflow region. r=birtles