#[markdown(off)]
Filed by: nerli [at] mozilla.com

https://treeherder.mozilla.org/logviewer.html#?job_id=228730350&repo=mozilla-inbound

https://queue.taskcluster.net/v1/task/LRpz_YoHRX2U2_dOPUGapw/runs/0/artifacts/public/logs/live_backing.log

[task 2019-02-15T21:33:59.905Z] 21:33:59 INFO - TEST-PASS | browser/modules/test/browser/browser_UsageTelemetry_urlbar_places.js | Should have found an entry for histogram index 3 - true == true -
[task 2019-02-15T21:33:59.908Z] 21:33:59 INFO - Leaving test bound test_switchtab
[task 2019-02-15T21:33:59.909Z] 21:33:59 INFO - Entering test bound test_tag
[task 2019-02-15T21:33:59.912Z] 21:33:59 INFO - Buffered messages finished
[task 2019-02-15T21:33:59.914Z] 21:33:59 INFO - TEST-UNEXPECTED-FAIL | browser/modules/test/browser/browser_UsageTelemetry_urlbar_places.js | Should not have recorded browser.engagement.navigation.urlbar - 1 == 0 - JS frame :: chrome://mochitests/content/browser/browser/modules/test/browser/browser_UsageTelemetry_urlbar_places.js :: assertSearchTelemetryEmpty :: line 29
[task 2019-02-15T21:33:59.915Z] 21:33:59 INFO - Stack trace:
[task 2019-02-15T21:33:59.917Z] 21:33:59 INFO - chrome://mochitests/content/browser/browser/modules/test/browser/browser_UsageTelemetry_urlbar_places.js:assertSearchTelemetryEmpty:29
[task 2019-02-15T21:33:59.919Z] 21:33:59 INFO - chrome://mochitests/content/browser/browser/modules/test/browser/browser_UsageTelemetry_urlbar_places.js:test_tag:214
[task 2019-02-15T21:33:59.920Z] 21:33:59 INFO - chrome://mochikit/content/browser-test.js:Tester_execTest/<:1106
[task 2019-02-15T21:33:59.921Z] 21:33:59 INFO - chrome://mochikit/content/browser-test.js:Tester_execTest:1134
[task 2019-02-15T21:33:59.923Z] 21:33:59 INFO - chrome://mochikit/content/browser-test.js:nextTest/<:995
[task 2019-02-15T21:33:59.925Z] 21:33:59 INFO - chrome://mochikit/content/tests/SimpleTest/SimpleTest.js:SimpleTest.waitForFocus/waitForFocusInner/focusedOrLoaded/<:803

This seems to be cause by Bug 1515083:
https://hg.mozilla.org/integration/autoland/rev/e90244ffbb13

https://treeherder.mozilla.org/#/jobs?repo=autoland&revision=a8d8de1df9e4f8ee5b671480d0a789d1631322b6

Tier 1 log file:
https://treeherder.mozilla.org/logviewer.html#/jobs?job_id=228811317&repo=mozilla-central&lineNumber=5623

[task 2019-02-16T10:59:58.524Z] 10:59:58 INFO - TEST-PASS | browser/modules/test/browser/browser_UsageTelemetry_urlbar_places.js | Should have found an entry for histogram index 3 - true == true -
[task 2019-02-16T10:59:58.525Z] 10:59:58 INFO - Leaving test bound test_tag
[task 2019-02-16T10:59:58.525Z] 10:59:58 INFO - Entering test bound test_visitURL
[task 2019-02-16T10:59:58.525Z] 10:59:58 INFO - Buffered messages finished
[task 2019-02-16T10:59:58.528Z] 10:59:58 INFO - TEST-UNEXPECTED-FAIL | browser/modules/test/browser/browser_UsageTelemetry_urlbar_places.js | Should not have recorded browser.engagement.navigation.urlbar - 1 == 0 - JS frame :: chrome://mochitests/content/browser/browser/modules/test/browser/browser_UsageTelemetry_urlbar_places.js :: assertSearchTelemetryEmpty :: line 29
[task 2019-02-16T10:59:58.529Z] 10:59:58 INFO - Stack trace:
[task 2019-02-16T10:59:58.530Z] 10:59:58 INFO - chrome://mochitests/content/browser/browser/modules/test/browser/browser_UsageTelemetry_urlbar_places.js:assertSearchTelemetryEmpty:29
[task 2019-02-16T10:59:58.530Z] 10:59:58 INFO - chrome://mochitests/content/browser/browser/modules/test/browser/browser_UsageTelemetry_urlbar_places.js:test_visitURL:233
[task 2019-02-16T10:59:58.531Z] 10:59:58 INFO - chrome://mochikit/content/browser-test.js:Tester_execTest/<:1106
[task 2019-02-16T10:59:58.532Z] 10:59:58 INFO - chrome://mochikit/content/browser-test.js:Tester_execTest:1134
[task 2019-02-16T10:59:58.533Z] 10:59:58 INFO - chrome://mochikit/content/browser-test.js:nextTest/<:995
[task 2019-02-16T10:59:58.534Z] 10:59:58 INFO - chrome://mochikit/content/tests/SimpleTest/SimpleTest.js:SimpleTest.waitForFocus/waitForFocusInner/focusedOrLoaded/<:803

Bug 1528255 fixed this (same issue).