central-as-beta simulation: https://treeherder.mozilla.org/logviewer.html#?job_id=303764005&repo=try

https://treeherder.mozilla.org/logviewer.html#?job_id=303764005&repo=try

[task 2020-05-26T13:43:56.686Z] 13:43:56 INFO - TEST-START | /html/canvas/offscreen/drawing-images-to-the-canvas/2d.drawImage.9arg.sourcesize.worker.html
[task 2020-05-26T13:43:56.701Z] 13:43:56 INFO - Closing window 440
[task 2020-05-26T13:43:56.701Z] 13:43:56 INFO - PID 6848 | ### XPCOM_MEM_BLOAT_LOG defined -- logging bloat/leaks to c:\users\task_1590498772\appdata\local\temp\tmpchhaxg\runtests_leaks_3384_tab_pid3420.log
[task 2020-05-26T13:43:56.702Z] 13:43:56 INFO - PID 6848 | [3420, Main Thread] WARNING: XPCOM_MEM_BLOAT_LOG is set, disabling native allocations.: file /builds/worker/checkouts/gecko/tools/profiler/core/platform.cpp, line 243
[task 2020-05-26T13:43:56.785Z] 13:43:56 INFO - PID 7488 | ###!!! [Parent][RunMessage] Error: Channel closing: too late to send/recv, messages will be lost
[task 2020-05-26T13:43:56.785Z] 13:43:56 INFO - PID 7488 | ###!!! [Parent][RunMessage] Error: Channel closing: too late to send/recv, messages will be lost
[task 2020-05-26T13:43:56.800Z] 13:43:56 INFO - PID 7488 | [Child 4248, Main Thread] WARNING: 'NS_FAILED(rv)', file /builds/worker/checkouts/gecko/widget/windows/nsLookAndFeel.cpp, line 855
[task 2020-05-26T13:43:56.815Z] 13:43:56 INFO - PID 7488 | [Child 4248, Main Thread] WARNING: 'NS_FAILED(GetAccentColor(unused))', file /builds/worker/checkouts/gecko/widget/windows/nsLookAndFeel.cpp, line 482
[task 2020-05-26T13:43:56.991Z] 13:43:56 INFO - PID 7488 | [Child 7560, Main Thread] WARNING: NS_ENSURE_SUCCESS(rv, rv) failed with result 0x80004005 (NS_ERROR_FAILURE): file /builds/worker/checkouts/gecko/netwerk/base/nsNetUtil.cpp, line 2295
[task 2020-05-26T13:43:56.991Z] 13:43:56 INFO - PID 7488 | [Child 7560, Main Thread] WARNING: 'NS_FAILED(rv)', file /builds/worker/checkouts/gecko/caps/ContentPrincipal.cpp, line 398
[task 2020-05-26T13:43:56.992Z] 13:43:56 INFO - PID 7488 | [Child 7560, Main Thread] WARNING: NS_ENSURE_SUCCESS(rv, rv) failed with result 0x80004005 (NS_ERROR_FAILURE): file /builds/worker/checkouts/gecko/caps/ContentPrincipal.cpp, line 423
[task 2020-05-26T13:43:57.012Z] 13:43:57 INFO - PID 7488 | [Child 7560, Main Thread] WARNING: Extra shutdown CC: 'i < NORMAL_SHUTDOWN_COLLECTIONS', file /builds/worker/checkouts/gecko/xpcom/base/nsCycleCollector.cpp, line 3359
[task 2020-05-26T13:43:57.039Z] 13:43:57 INFO - PID 7488 | ### XPCOM_MEM_BLOAT_LOG defined -- logging bloat/leaks to c:\users\task_1590498772\appdata\local\temp\tmp4djovh\runtests_leaks_3384_tab_pid5548.log
[task 2020-05-26T13:43:57.039Z] 13:43:57 INFO - PID 7488 | [5548, Main Thread] WARNING: XPCOM_MEM_BLOAT_LOG is set, disabling native allocations.: file /builds/worker/checkouts/gecko/tools/profiler/core/platform.cpp, line 243
[task 2020-05-26T13:43:57.061Z] 13:43:57 INFO - PID 6848 | [Child 4120, Main Thread] WARNING: NS_ENSURE_TRUE(request) failed: file /builds/worker/checkouts/gecko/netwerk/base/nsLoadGroup.cpp, line 595
[task 2020-05-26T13:43:57.136Z] 13:43:57 INFO - PID 7488 | [Parent 7072, Main Thread] WARNING: Not resolving response because actor is dead.: file /builds/worker/workspace/obj-build/ipc/ipdl/PContentParent.cpp, line 11527
[task 2020-05-26T13:43:57.163Z] 13:43:57 INFO - PID 6848 | [Child 4120, Main Thread] WARNING: NS_ENSURE_TRUE(request) failed: file /builds/worker/checkouts/gecko/netwerk/base/nsLoadGroup.cpp, line 595
[task 2020-05-26T13:43:57.221Z] 13:43:57 INFO - PID 7488 | [Parent 7072, Main Thread] WARNING: Not resolving response because actor is dead.: file /builds/worker/workspace/obj-build/ipc/ipdl/PContentParent.cpp, line 11527
[task 2020-05-26T13:43:57.268Z] 13:43:57 INFO - PID 7488 | [Parent 7072, Main Thread] WARNING: Not resolving response because actor is dead.: file /builds/worker/workspace/obj-build/ipc/ipdl/PContentParent.cpp, line 11527
[task 2020-05-26T13:43:57.504Z] 13:43:57 INFO -
[task 2020-05-26T13:43:57.504Z] 13:43:57 INFO - TEST-UNEXPECTED-FAIL | /html/cross-origin-embedder-policy/reporting-navigation.https.html | Navigation CORP - promise_test: Unhandled rejection with value: object "TypeError: global.ReportingObserver is not a constructor"
[task 2020-05-26T13:43:57.505Z] 13:43:57 INFO - TEST-INFO | expected TIMEOUT
[task 2020-05-26T13:43:57.505Z] 13:43:57 INFO -
[task 2020-05-26T13:43:57.505Z] 13:43:57 INFO - TEST-UNEXPECTED-FAIL | /html/cross-origin-embedder-policy/reporting-navigation.https.html | Navigation CORP and about:blank - promise_test: Unhandled rejection with value: object "TypeError: global.ReportingObserver is not a constructor"
[task 2020-05-26T13:43:57.505Z] 13:43:57 INFO - TEST-INFO | expected NOTRUN
[task 2020-05-26T13:43:57.506Z] 13:43:57 INFO - TEST-UNEXPECTED-OK | /html/cross-origin-embedder-policy/reporting-navigation.https.html | expected TIMEOUT

Might also need to be tracked in bug 1631751?

Thanks!

Changing the priority to p2 as the bug is tracked by a release manager for the current nightly.
See What Do You Triage for more information

Depends on D76858

Comment on attachment 9152488 [details]
Bug 1640928 - Expectation update for reporting-subresource-corp.https.html because ReportingObserver not available on Beta and Release. r=jgraham DONTBUILD

Revision D77313 was moved to bug 1641629. Setting attachment 9152488 [details] to obsolete.

https://hg.mozilla.org/mozilla-central/rev/872b96bf4223

Verified fixed in latest beta sim: https://treeherder.mozilla.org/#/jobs?repo=try&group_state=expanded&resultStatus=success%2Ctestfailed%2Cbusted%2Cexception%2Cretry%2Cusercancel%2Crunnable&revision=e0e9d067faca2cbe2daa85699a46e92a529263c9&searchStr=win%2C7%2Cdebug%2Cwpt&selectedTaskRun=E3LW8Q7eRXGJxeJL8BMJxw-0