Filed by: egao [at] mozilla.com
Parsed log: https://treeherder.mozilla.org/logviewer.html#?job_id=251074328&repo=try
Full log: https://queue.taskcluster.net/v1/task/MSgzLG2BQAa3UuzSunBogw/runs/0/artifacts/public/logs/live_backing.log

Context:
02:15:56 INFO - TEST-START | ThreadMetrics.CollectMetrics
02:15:56 WARNING - TEST-UNEXPECTED-FAIL | ThreadMetrics.CollectMetrics | Expected: (duration) < (200000u), actual: 278857 vs 200000 @ /builds/worker/workspace/build/src/xpcom/tests/gtest/TestThreadMetrics.cpp:153
02:15:56 WARNING - TEST-UNEXPECTED-FAIL | ThreadMetrics.CollectMetrics | test completed (time: 279ms)
02:15:56 INFO - TEST-START | ThreadMetrics.CollectRecursiveMetrics
02:15:56 WARNING - TEST-UNEXPECTED-FAIL | ThreadMetrics.CollectRecursiveMetrics | Expected: (duration) < (200000u), actual: 201243 vs 200000 @ /builds/worker/workspace/build/src/xpcom/tests/gtest/TestThreadMetrics.cpp:184
02:15:56 WARNING - TEST-UNEXPECTED-FAIL | ThreadMetrics.CollectRecursiveMetrics | test completed (time: 500ms)

Both ThreadMetrics.CollectMetrics and ThreadMetrics.CollectRecursiveMetrics appear to pass as expected on both macosx1014-64-shippable and macosx1014-64/debug as of mozilla-central 893a79647962f1917bdde65957fed18e5afd1d5a.

Will continue observation of these tests, if failures do not reappear by EOD Wednesday (June 26) I will close this bug.

This failure is observable on macosx1014-64-ccov/debug, as per :bwc's push: https://treeherder.mozilla.org/#/jobs?repo=try&revision=398fb3a4df9de9704ca2b099804643172a28a84a&selectedJob=255588478

However since we are not running any tests on macosx1014-64-ccov/debug I think it's safe to ignore this failure for the time being.