Filed by: apavel [at] mozilla.com
Parsed log: https://treeherder.mozilla.org/logviewer.html#?job_id=275508879&repo=mozilla-central
Full log: https://firefox-ci-tc.services.mozilla.com/api/queue/v1/task/HY4i-oYsRuGM328B2a8zeA/runs/0/artifacts/public/logs/live_backing.log

[task 2019-11-10T00:09:42.486Z] 00:09:42 INFO - TEST-START | dom/media/test/test_info_leak.html
[task 2019-11-10T00:12:46.635Z] 00:12:46 INFO - TEST-INFO | started process screenshot
[task 2019-11-10T00:12:46.710Z] 00:12:46 INFO - TEST-INFO | screenshot: exit 0
[task 2019-11-10T00:12:46.710Z] 00:12:46 INFO - <snipped 11 output lines - if you need more context, please use SimpleTest.requestCompleteLog() in your test>
[task 2019-11-10T00:12:46.711Z] 00:12:46 INFO - Buffered messages logged at 00:09:42
[task 2019-11-10T00:12:46.711Z] 00:12:46 INFO - TEST-PASS | dom/media/test/test_info_leak.html | Z:\task_1573343577\build\tests\mochitest\tests\dom\media\test\404.ogv Too many events received
[task 2019-11-10T00:12:46.711Z] 00:12:46 INFO - TEST-PASS | dom/media/test/test_info_leak.html | Z:\task_1573343577\build\tests\mochitest\tests\dom\media\test\404.ogv Events received in wrong order
[task 2019-11-10T00:12:46.712Z] 00:12:46 INFO - Z:\task_1573343577\build\tests\mochitest\tests\dom\media\test\320x240.ogv: got error
[task 2019-11-10T00:12:46.712Z] 00:12:46 INFO - TEST-PASS | dom/media/test/test_info_leak.html | Z:\task_1573343577\build\tests\mochitest\tests\dom\media\test\320x240.ogv Too many events received
[task 2019-11-10T00:12:46.712Z] 00:12:46 INFO - TEST-PASS | dom/media/test/test_info_leak.html | Z:\task_1573343577\build\tests\mochitest\tests\dom\media\test\320x240.ogv Events received in wrong order
[task 2019-11-10T00:12:46.713Z] 00:12:46 INFO - TEST-FAIL | dom/media/test/test_info_leak.html | The author of the test has indicated that flaky timeouts are expected. Reason: untriaged
[task 2019-11-10T00:12:46.713Z] 00:12:46 INFO - Z:\task_1573343577\build\tests\mochitest\tests\dom\media\test\404.ogv: got error
[task 2019-11-10T00:12:46.713Z] 00:12:46 INFO - TEST-PASS | dom/media/test/test_info_leak.html | Z:\task_1573343577\build\tests\mochitest\tests\dom\media\test\404.ogv Too many events received
[task 2019-11-10T00:12:46.713Z] 00:12:46 INFO - TEST-PASS | dom/media/test/test_info_leak.html | Z:\task_1573343577\build\tests\mochitest\tests\dom\media\test\404.ogv Events received in wrong order
[task 2019-11-10T00:12:46.714Z] 00:12:46 INFO - TEST-FAIL | dom/media/test/test_info_leak.html | The author of the test has indicated that flaky timeouts are expected. Reason: untriaged

[task 2019-11-10T00:12:46.742Z] 00:12:46 INFO - TEST-PASS | dom/media/test/test_info_leak.html | 404.wav Too many events received
[task 2019-11-10T00:12:46.743Z] 00:12:46 INFO - TEST-PASS | dom/media/test/test_info_leak.html | 404.wav Events received in wrong order
[task 2019-11-10T00:12:46.743Z] 00:12:46 INFO - Buffered messages logged at 00:09:49
[task 2019-11-10T00:12:46.743Z] 00:12:46 INFO - 404.ogv: got stalled
[task 2019-11-10T00:12:46.743Z] 00:12:46 INFO - 404.wav: got stalled
[task 2019-11-10T00:12:46.744Z] 00:12:46 INFO - Buffered messages finished
[task 2019-11-10T00:12:46.745Z] 00:12:46 INFO - TEST-UNEXPECTED-FAIL | dom/media/test/test_info_leak.html | Test timed out!
[task 2019-11-10T00:12:46.745Z] 00:12:46 INFO - SimpleTest.ok@SimpleTest/SimpleTest.js:277:18
[task 2019-11-10T00:12:46.745Z] 00:12:46 INFO - onTimeout@dom/media/test/manifest.js:2086:9
[task 2019-11-10T00:12:46.745Z] 00:12:46 INFO - setTimeout handlerMediaTestManager/this.started@dom/media/test/manifest.js:2093:57
[task 2019-11-10T00:12:46.746Z] 00:12:46 INFO - startTest@dom/media/test/test_info_leak.html:161:11
[task 2019-11-10T00:12:46.746Z] 00:12:46 INFO - MediaTestManager/this.nextTest@dom/media/test/manifest.js:2167:12
[task 2019-11-10T00:12:46.746Z] 00:12:46 INFO - MediaTestManager/this.finished@dom/media/test/manifest.js:2139:12
[task 2019-11-10T00:12:46.746Z] 00:12:46 INFO - finish@dom/media/test/test_info_leak.html:71:11
[task 2019-11-10T00:12:46.746Z] 00:12:46 INFO - listener/<@dom/media/test/test_info_leak.html:95:34
[task 2019-11-10T00:12:46.746Z] 00:12:46 INFO - setTimeout handlerSimpleTest_setTimeoutShim@SimpleTest/SimpleTest.js:686:43
[task 2019-11-10T00:12:46.746Z] 00:12:46 INFO - listener@dom/media/test/test_info_leak.html:95:15
[task 2019-11-10T00:12:46.746Z] 00:12:46 INFO - EventListener.handleEventcreateMedia@dom/media/test/test_info_leak.html:103:7
[task 2019-11-10T00:12:46.747Z] 00:12:46 INFO - startTest@dom/media/test/test_info_leak.html:163:14
[task 2019-11-10T00:12:46.747Z] 00:12:46 INFO - MediaTestManager/this.nextTest@dom/media/test/manifest.js:2167:12
[task 2019-11-10T00:12:46.747Z] 00:12:46 INFO - MediaTestManager/this.finished@dom/media/test/manifest.js:2139:12
[task 2019-11-10T00:12:46.747Z] 00:12:46 INFO - finish@dom/media/test/test_info_leak.html:71:11
[task 2019-11-10T00:12:46.747Z] 00:12:46 INFO - listener/<@dom/media/test/test_info_leak.html:95:34
[task 2019-11-10T00:12:46.747Z] 00:12:46 INFO - setTimeout handlerSimpleTest_setTimeoutShim@SimpleTest/SimpleTest.js:686:43
[task 2019-11-10T00:12:46.748Z] 00:12:46 INFO - listener@dom/media/test/test_info_leak.html:95:15
[task 2019-11-10T00:12:46.748Z] 00:12:46 INFO - EventListener.handleEventcreateMedia@dom/media/test/test_info_leak.html:103:7
[task 2019-11-10T00:12:46.748Z] 00:12:46 INFO - startTest@dom/media/test/test_info_leak.html:163:14
[task 2019-11-10T00:12:46.748Z] 00:12:46 INFO - MediaTestManager/this.nextTest@dom/media/test/manifest.js:2167:12
[task 2019-11-10T00:12:46.748Z] 00:12:46 INFO - MediaTestManager/this.finished@dom/media/test/manifest.js:2139:12
[task 2019-11-10T00:12:46.748Z] 00:12:46 INFO - finish@dom/media/test/test_info_leak.html:71:11
[task 2019-11-10T00:12:46.748Z] 00:12:46 INFO - listener/<@dom/media/test/test_info_leak.html:95:34
[task 2019-11-10T00:12:46.748Z] 00:12:46 INFO - setTimeout handlerSimpleTest_setTimeoutShim@SimpleTest/SimpleTest.js:686:43
[task 2019-11-10T00:12:46.749Z] 00:12:46 INFO - listener@dom/media/test/test_info_leak.html:95:15
[task 2019-11-10T00:12:46.749Z] 00:12:46 INFO - EventListener.handleEventcreateMedia@dom/media/test/test_info_leak.html:103:7
[task 2019-11-10T00:12:46.749Z] 00:12:46 INFO - startTest@dom/media/test/test_info_leak.html:163:14
[task 2019-11-10T00:12:46.749Z] 00:12:46 INFO - MediaTestManager/this.nextTest@dom/media/test/manifest.js:2167:12
[task 2019-11-10T00:12:46.749Z] 00:12:46 INFO - MediaTestManager/this.finished@dom/media/test/manifest.js:2139:12
[task 2019-11-10T00:12:46.749Z] 00:12:46 INFO - finish@dom/media/test/test_info_leak.html:71:11
[task 2019-11-10T00:12:46.749Z] 00:12:46 INFO - listener/<@dom/media/test/test_info_leak.html:95:34
[task 2019-11-10T00:12:46.749Z] 00:12:46 INFO - setTimeout handlerSimpleTest_setTimeoutShim@SimpleTest/SimpleTest.js:686:43
[task 2019-11-10T00:12:46.749Z] 00:12:46 INFO - listener@dom/media/test/test_info_leak.html:95:15
[task 2019-11-10T00:12:46.749Z] 00:12:46 INFO - EventListener.handleEventcreateMedia@dom/media/test/test_info_leak.html:103:7
[task 2019-11-10T00:12:46.750Z] 00:12:46 INFO - startTest@dom/media/test/test_info_leak.html:163:14
[task 2019-11-10T00:12:46.750Z] 00:12:46 INFO - MediaTestManager/this.nextTest@dom/media/test/manifest.js:2167:12
[task 2019-11-10T00:12:46.750Z] 00:12:46 INFO - MediaTestManager/this.runTests/<@dom/media/test/manifest.js:2062:12
[task 2019-11-10T00:12:46.750Z] 00:12:46 INFO - AsyncMediaTestManager/this.runTests@dom/media/test/manifest.js:2061:19
[task 2019-11-10T00:12:46.750Z] 00:12:46 INFO - @dom/media/test/test_info_leak.html:168:11
[task 2019-11-10T00:12:46.750Z] 00:12:46 INFO - http://localhost/404.ogv-8 timed out!
[task 2019-11-10T00:12:46.751Z] 00:12:46 INFO - {"EMEInfo":{"keySystem":"","sessionsInfo":""},"compositorDroppedFrames":0,"decoder":{"PlayState":"","channels":0,"containerType":"","hasAudio":false,"hasVideo":false,"instance":"","rate":0,"reader":{"audioChannels":0,"audioDecoderName":"","audioFramesDecoded":0,"audioRate":0,"audioState":{"demuxEOS":0,"demuxQueueSize":0,"drainState":0,"hasDecoder":false,"hasDemuxRequest":false,"hasPromise":false,"lastStreamSourceID":0,"needInput":false,"numSamplesInput":0,"numSamplesOutput":0,"pending":0,"queueSize":0,"timeTreshold":0,"timeTresholdHasSeeked":false,"waitingForData":false,"waitingForKey":false,"waitingPromise":false},"audioType":"","frameStats":{"droppedCompositorFrames":0,"droppedDecodedFrames":0,"droppedSinkFrames":0},"videoDecoderName":"","videoHardwareAccelerated":false,"videoHeight":0,"videoNumSamplesOutputTotal":0,"videoNumSamplesSkippedTotal":0,"videoRate":0,"videoState":{"demuxEOS":0,"demuxQueueSize":0,"drainState":0,"hasDecoder":false,"hasDemuxRequest":false,"hasPromise":false,"lastStreamSourceID":0,"needInput":false,"numSamplesInput":0,"numSamplesOutput":0,"pending":0,"queueSize":0,"timeTreshold":0,"timeTresholdHasSeeked":false,"waitingForData":false,"waitingForKey":false,"waitingPromise":false},"videoType":"","videoWidth":0},"resource":{"cacheStream":{"cacheSuspended":false,"channelEnded":false,"channelOffset":0,"loadID":0,"streamLength":0}},"stateMachine":{"audioCompleted":false,"audioRequestStatus":"","clock":0,"decodedAudioEndTime":0,"decodedVideoEndTime":0,"duration":0,"isPlaying":false,"mediaSink":{"audioSinkWrapper":{"audioEnded":false,"audioSink":{"audioEnded":false,"hasErrored":false,"isPlaying":false,"isStarted":false,"lastGoodPosition":0,"outputRate":0,"playbackComplete":false,"startTime":0,"written":0},"isPlaying":false,"isStarted":false},"decodedStream":{"audioQueueFinished":false,"audioQueueSize":0,"data":{"audioFramesWritten":0,"haveSentFinishAudio":false,"haveSentFinishVideo":false,"instance":"","lastVideoEndTime":0,"lastVideoStartTime":0,"nextAudioTime":0,"streamAudioWritten":0,"streamVideoWritten":0},"instance":"","lastAudio":0,"lastOutputTime":0,"playing":0,"startTime":0},"videoSink":{"endPromiseHolderIsEmpty":false,"finished":false,"hasVideo":false,"isPlaying":false,"isStarted":false,"size":0,"videoFrameEndTime":0,"videoSinkEndRequestExists":false}},"mediaTime":0,"playState":0,"sentFirstFrameLoadedEvent":false,"state":"","stateObj":{"isPrerolling":false},"videoCompleted":false,"videoRequestStatus":""}}}
[task 2019-11-10T00:12:46.751Z] 00:12:46 INFO - [finished http://localhost/404.ogv-8] remaining= http://localhost/404.wav-9
[task 2019-11-10T00:12:46.751Z] 00:12:46 INFO - TEST-PASS | dom/media/test/test_info_leak.html | [finished http://localhost/404.ogv-8 t=184.091] Length of array should match number of running tests
[task 2019-11-10T00:12:46.751Z] 00:12:46 INFO - TEST-PASS | dom/media/test/test_info_leak.html | [started http://localhost/404.webm-10 t=184.093] Length of array should match number of running tests
[task 2019-11-10T00:12:46.752Z] 00:12:46 INFO - Testing: video/webm @ http://localhost/404.webm
[task 2019-11-10T00:12:46.752Z] 00:12:46 INFO - Not taking screenshot here: see the one that was previously logged
[task 2019-11-10T00:12:46.752Z] 00:12:46 INFO - TEST-UNEXPECTED-FAIL | dom/media/test/test_info_leak.html | Test timed out!

Seems to be fixed by commit https://hg.mozilla.org/mozilla-central/rev/7a75cab3dd550b77ba4f748b31c1b45ce2784c84

https://treeherder.mozilla.org/#/jobs?repo=mozilla-central&resultStatus=success%2Ctestfailed%2Cbusted%2Cexception&searchStr=mda%2Cwindows&group_state=expanded&selectedJob=275513811