Filed by: dluca [at] mozilla.com
Parsed log: https://treeherder.mozilla.org/logviewer.html#?job_id=303345219&repo=autoland
Full log: https://firefox-ci-tc.services.mozilla.com/api/queue/v1/task/GggqGogWSHWlPIkTziHYcg/runs/0/artifacts/public/logs/live_backing.log
Reftest URL: https://hg.mozilla.org/mozilla-central/raw-file/tip/layout/tools/reftest/reftest-analyzer.xhtml#logurl=https://firefox-ci-tc.services.mozilla.com/api/queue/v1/task/GggqGogWSHWlPIkTziHYcg/runs/0/artifacts/public/logs/live_backing.log&only_show_unexpected=1

 INFO -  REFTEST TEST-START | dom/base/crashtests/1529203-2.html
[task 2020-05-22T10:10:00.118Z] 10:10:00     INFO -  REFTEST INFO | SET PREFERENCE pref(dom.disable_open_during_load,false)
[task 2020-05-22T10:10:00.118Z] 10:10:00     INFO -  REFTEST INFO | SET PREFERENCE pref(browser.link.open_newwindow,2)
[task 2020-05-22T10:10:00.118Z] 10:10:00     INFO -  REFTEST TEST-LOAD | http://10.0.2.2:8854/tests/dom/base/crashtests/1529203-2.html | 0 / 1 (0%)
[task 2020-05-22T10:15:05.493Z] 10:15:05  WARNING -  REFTEST TEST-UNEXPECTED-FAIL | dom/base/crashtests/1529203-2.html | load failed: timed out waiting for reftest-wait to be removed
[task 2020-05-22T10:15:05.493Z] 10:15:05     INFO -  REFTEST INFO | Saved log: START http://10.0.2.2:8854/tests/dom/base/crashtests/1529203-2.html
[task 2020-05-22T10:15:05.493Z] 10:15:05     INFO -  REFTEST INFO | Saved log: [CONTENT] Using browser remote=true
[task 2020-05-22T10:15:05.493Z] 10:15:05     INFO -  REFTEST INFO | Saved log: [CONTENT] OnDocumentLoad triggering WaitForTestEnd
[task 2020-05-22T10:15:05.493Z] 10:15:05     INFO -  REFTEST INFO | Saved log: [CONTENT] WaitForTestEnd: Adding listeners
[task 2020-05-22T10:15:05.493Z] 10:15:05     INFO -  REFTEST INFO | Saved log: Initializing canvas snapshot
[task 2020-05-22T10:15:05.494Z] 10:15:05     INFO -  REFTEST INFO | Saved log: [CONTENT] MakeProgress
[task 2020-05-22T10:15:05.494Z] 10:15:05     INFO -  REFTEST INFO | Saved log: [CONTENT] MakeProgress: STATE_WAITING_TO_FIRE_INVALIDATE_EVENT
[task 2020-05-22T10:15:05.494Z] 10:15:05     INFO -  REFTEST INFO | Saved log: [CONTENT] MakeProgress: dispatching MozReftestInvalidate
[task 2020-05-22T10:15:05.494Z] 10:15:05     INFO -  REFTEST INFO | Saved log: [CONTENT] MakeProgress
[task 2020-05-22T10:15:05.494Z] 10:15:05     INFO -  REFTEST INFO | Saved log: [CONTENT] MakeProgress: STATE_WAITING_FOR_REFTEST_WAIT_REMOVAL
[task 2020-05-22T10:15:05.494Z] 10:15:05     INFO -  REFTEST INFO | Saved log: [CONTENT] MakeProgress: waiting for reftest-wait to be removed
[task 2020-05-22T10:15:05.495Z] 10:15:05     INFO -  REFTEST INFO | Saved log: [CONTENT] AfterPaintListener in http://10.0.2.2:8854/tests/dom/base/crashtests/1529203-2.html
[task 2020-05-22T10:15:05.495Z] 10:15:05     INFO -  REFTEST INFO | Saved log: [CONTENT] HandlePendingTasksAfterMakeProgress updating canvas
[task 2020-05-22T10:15:05.495Z] 10:15:05     INFO -  REFTEST INFO | Saved log: [CONTENT] SendUpdateCanvasForEvent with 1 rects
[task 2020-05-22T10:15:05.495Z] 10:15:05     INFO -  REFTEST INFO | Saved log: [CONTENT] Rect: 0 0 800 1000
[task 2020-05-22T10:15:05.495Z] 10:15:05     INFO -  REFTEST INFO | Saved log: Updating canvas for invalidation
[task 2020-05-22T10:15:05.495Z] 10:15:05     INFO -  REFTEST INFO | Saved log: [CONTENT] MakeProgress
[task 2020-05-22T10:15:05.495Z] 10:15:05     INFO -  REFTEST INFO | Saved log: [CONTENT] MakeProgress: STATE_WAITING_FOR_REFTEST_WAIT_REMOVAL
[task 2020-05-22T10:15:05.495Z] 10:15:05     INFO -  REFTEST INFO | Saved log: [CONTENT] MakeProgress: waiting for reftest-wait to be removed
[task 2020-05-22T10:15:05.496Z] 10:15:05     INFO -  REFTEST TEST-END | dom/base/crashtests/1529203-2.html
[task 2020-05-22T10:15:05.496Z] 10:15:05     INFO -  REFTEST INFO | RESTORE PREFERENCE pref(browser.link.open_newwindow,3)
[task 2020-05-22T10:15:05.496Z] 10:15:05     INFO -  REFTEST INFO | RESTORE PREFERENCE pref(dom.disable_open_during_load,true)
[task 2020-05-22T10:15:05.496Z] 10:15:05     INFO -  REFTEST INFO | Result summary:
[task 2020-05-22T10:15:05.496Z] 10:15:05     INFO -  REFTEST INFO | Successful: 0 (0 pass, 0 load only)
[task 2020-05-22T10:15:05.496Z] 10:15:05  WARNING -  REFTEST INFO | Unexpected: 1 (0 unexpected fail, 0 unexpected pass, 0 unexpected asserts, 1 failed load, 0 exception)
[task 2020-05-22T10:15:05.496Z] 10:15:05  WARNING -  One or more unittests failed.
[task 2020-05-22T10:15:05.496Z] 10:15:05     INFO -  REFTEST INFO | Known problems: 0 (0 known fail, 0 known asserts, 0 random, 0 skipped, 0 slow)
[task 2020-05-22T10:15:05.496Z] 10:15:05     INFO -  REFTEST SUITE-END | Shutdown
[task 2020-05-22T10:15:05.496Z] 10:15:05     INFO -  REFTEST INFO | Slowest test took 0ms (undefined)
[task 2020-05-22T10:15:05.496Z] 10:15:05     INFO -  REFTEST INFO | Total canvas count = 0
[task 2020-05-22T10:15:05.496Z] 10:15:05     INFO -  wait for org.mozilla.geckoview.test complete; top activity=com.android.launcher3
[task 2020-05-22T10:15:05.599Z] 10:15:05     INFO -  remoteautomation.py | Application ran for: 0:05:10.189261
[task 2020-05-22T10:15:07.199Z] 10:15:07     INFO -  leakcheck | refcount logging is off, so leaks can't be detected!
[task 2020-05-22T10:15:07.199Z] 10:15:07     INFO -  REFTEST INFO | :::
[task 2020-05-22T10:15:07.199Z] 10:15:07     INFO -  REFTEST INFO | ::: Running test verification step "2. Run each test 5 times in a new browser each time."...
[task 2020-05-22T10:15:07.199Z] 10:15:07     INFO -  REFTEST INFO | :::
[task 2020-05-22T10:15:10.903Z] 10:15:10     INFO -  REFTEST INFO | Running with e10s: True
[task 2020-05-22T10:15:11.218Z] 10:15:11     INFO -  Granting important runtime permissions to org.mozilla.geckoview.test
[task 2020-05-22T10:15:13.046Z] 10:15:13     INFO -  launch_application: am start -W -n org.mozilla.geckoview.test/org.mozilla.geckoview.test.TestRunnerActivity -a android.intent.action.MAIN --es env9 MOZ_DEVELOPER_REPO_DIR=tests --es env8 MOZ_CRASHREPORTER_NO_REPORT=1 --es args "-no-remote -profile /data/local/tmp/tests/reftest/profile/" --es env3 R_LOG_VERBOSE=1 --es env2 XPCOM_DEBUG_BREAK=stack --es env1 MOZ_WEBRENDER=0 --es env0 MOZ_CRASHREPORTER=1 --es env7 R_LOG_DESTINATION=stderr --es env6 MOZ_CRASHREPORTER_SHUTDOWN=1 --es env5 MOZ_IN_AUTOMATION=1 --es env4 MOZ_DISABLE_NONLOCAL_CONNECTIONS=1 --ez use_multiprocess True --es env10 R_LOG_LEVEL=6
[task 2020-05-22T10:15:14.059Z] 10:15:14     INFO -  remoteautomation.py | Application pid: 3500
[task 2020-05-22T10:15:16.114Z] 10:15:16     INFO -  REFTEST INFO | Reading manifest http://10.0.2.2:8854/tests/dom/base/crashtests/crashtests.list
[task 2020-05-22T10:15:16.114Z] 10:15:16     INFO -  REFTEST INFO | Dumping JSON representation of sandbox
[task 2020-05-22T10:15:16.115Z] 10:15:16     INFO -  REFTEST INFO | {"isDebugBuild":true,"xulRuntime":{"widgetToolkit":"android","OS":"Android","XPCOMABI":"x86_64-gcc3"},"smallScreen":false,"d2d":false,"dwrite":false,"gpuProcess":false,"azureCairo":false,"azureSkia":true,"skiaContent":true,"azureSkiaGL":false,"contentSameGfxBackendAsCanvas":true,"remoteCanvas":false,"layersGPUAccelerated":true,"d3d11":false,"d3d9":false,"layersOpenGL":true,"webrender":false,"layersOMTC":true,"advancedLayers":false,"layerChecksEnabled":true,"retainedDisplayList":true,"usesOverlayScrollbars":true,"Android":true,"cocoaWidget":false,"gtkWidget":false,"qtWidget":false,"winWidget":false,"is64Bit":true,"geckoview":true,"transparentScrollbars":false,"AndroidVersion":24,"emulator":true,"device":false,"AddressSanitizer":false,"webrtc":true,"retainedDisplayLists":true,"compareRetainedDisplayLists":false,"skiaPdf":false,"release_or_beta":false,"http":{"userAgent":"Mozilla/5.0 (Android 7.0; Mobile; rv:78.0) Gecko/78.0 Firefox/78.0","appName":"Mozilla","appVersion":"5.0","platform":"Android 7.0","oscpu":"Linux x86_64","misc":"rv:78.0"},"haveTestPlugin":false,"windowsDefaultTheme":false,"nativeThemePref":false,"gpuProcessForceEnabled":false,"prefs":{},"browserIsRemote":true,"browserIsFission":false,"asyncPan":true,"usesRepeatResampling":false,"verify":true,"fission":false,"serviceWorkerE10s":true}
[task 2020-05-22T10:15:16.115Z] 10:15:16     INFO -  REFTEST SUITE-START | Running 1 tests
[task 2020-05-22T10:15:16.115Z] 10:15:16     INFO -  REFTEST TEST-START | dom/base/crashtests/1529203-2.html

Fixed by backout:
https://hg.mozilla.org/integration/autoland/rev/0c7f55b96d599ccdf605abd903ed3b6a62187ae3