Filed by: rvandermeulen [at] mozilla.com https://treeherder.mozilla.org/logviewer.html#?job_id=102033248&repo=mozilla-inbound https://queue.taskcluster.net/v1/task/fe6aHN5oRm6LKKkxOkp6IA/runs/0/artifacts/public/logs/live_backing.log

Mass change P3->P4 to align with new Mozilla triage process.

I am confused why this is in webrender instead of audio/video recording, but I will trust that this is there for a reason. :kats, this is one of our high frequency failures, can you help prioritize this and get someone to work on a fix when appropriate?

(In reply to Joel Maher ( :jmaher) (UTC-5) from comment #10) > I am confused why this is in webrender instead of audio/video recording, but > I will trust that this is there for a reason. The reason is this: (In reply to OrangeFactor Robot from comment #9) > Platform breakdown: > * linux64-qr: 40 > If it only happens on linux64-qr, it's more likely to be a webrender bug than an audio/video bug. I'll see what I can do about this (which will probably be a cursory investigation followed by disabling the test pending a more detailed investigation).

I can't repro the failure locally. But walking through the test and looking at the output, it seems that the video that is made from capturing the canvas is incomplete. The canvas is supposed to go through three resizes (although since it starts at 100x100 I would have expected it to be only two resizes) but it doesn't seem to capture any frames at the last size. So then when the test walks through the video it only fires two resize events instead of the expected 3. At this point my best guess is that assuming the recording involves readback, webrender slows this down enough that the 100ms [1] time is exceeded, which I think would result in the behaviour observed. [1] http://searchfox.org/mozilla-central/rev/e62604a97286f49993eb29c493672c17c7398da9/dom/media/test/test_mediarecorder_record_changing_video_resolution.html#134

Comment on attachment 8915142 [details] Bug 1367879 - Skip test that fails frequently with webrender enabled. https://reviewboard.mozilla.org/r/186388/#review191442

Pushed by kgupta@mozilla.com: https://hg.mozilla.org/integration/autoland/rev/7c4fffd110b6 Skip test that fails frequently with webrender enabled. r=jmaher