Bug: Intermittent browser/base/content/test/performance/browser_preferences_usage.js | toolkit.telemetry.cachedClientID should not be accessed more than 40 times. - 57 <= 40 - JS frame :: /performance/browser_preferences_usage.js :: checkPrefGetters :: line
Status: RESOLVED
Priority: P5
Resolution: INCOMPLETE
Created: 2021-03-19 19:20:11+00:00
Resolved: 2021-06-15 17:02:37+00:00

**Filed by:** malexandru [at] mozilla.com
**Parsed log:** https://treeherder.mozilla.org/logviewer?job_id=333803145&repo=autoland
**Full log:** https://firefox-ci-tc.services.mozilla.com/api/queue/v1/task/Orfwwl8XToCO7wN1dgmRmA/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/Orfwwl8XToCO7wN1dgmRmA/runs/0/artifacts/public/logs/live_backing.log&only_show_unexpected=1

---
```
[task 2021-03-19T18:26:31.940Z] 18:26:31     INFO - checking window state
[task 2021-03-19T18:26:32.324Z] 18:26:32     INFO - TEST-START | browser/base/content/test/performance/browser_preferences_usage.js
[task 2021-03-19T18:26:33.650Z] 18:26:33     INFO - GECKO(1834) | [1846, MainThread] WARNING: XPCOM objects created/destroyed from static ctor/dtor: file /builds/worker/checkouts/gecko/xpcom/base/nsTraceRefcnt.cpp:202
[task 2021-03-19T18:26:33.650Z] 18:26:33     INFO - GECKO(1834) | [1846, MainThread] WARNING: XPCOM objects created/destroyed from static ctor/dtor: file /builds/worker/checkouts/gecko/xpcom/base/nsTraceRefcnt.cpp:202
[task 2021-03-19T18:26:33.651Z] 18:26:33     INFO - GECKO(1834) | ### XPCOM_MEM_BLOAT_LOG defined -- logging bloat/leaks to /var/folders/lf/p5fbzdqs7m583jpg2_nhp12w000017/T/tmpOLvtJx.mozrunner/runtests_leaks_tab_pid1846.log
[task 2021-03-19T18:26:33.651Z] 18:26:33     INFO - GECKO(1834) | [1846, MainThread] WARNING: XPCOM objects created/destroyed from static ctor/dtor: file /builds/worker/checkouts/gecko/xpcom/base/nsTraceRefcnt.cpp:202
[task 2021-03-19T18:26:33.651Z] 18:26:33     INFO - GECKO(1834) | [1846, MainThread] WARNING: XPCOM objects created/destroyed from static ctor/dtor: file /builds/worker/checkouts/gecko/xpcom/base/nsTraceRefcnt.cpp:202
[task 2021-03-19T18:26:33.651Z] 18:26:33     INFO - GECKO(1834) | [1846, Main Thread] WARNING: XPCOM_MEM_BLOAT_LOG is set, disabling native allocations.: file /builds/worker/checkouts/gecko/tools/profiler/core/platform.cpp:251
[task 2021-03-19T18:26:33.767Z] 18:26:33     INFO - GECKO(1834) | Waiting for browser load
[task 2021-03-19T18:26:33.768Z] 18:26:33     INFO - GECKO(1834) | Waiting for browser state change
[task 2021-03-19T18:26:33.813Z] 18:26:33     INFO - GECKO(1834) | [Child 1846: Main Thread]: I/DocShellAndDOMWindowLeak ++DOCSHELL 110cf3400 == 1 [pid = 1846] [id = 0]
[task 2021-03-19T18:26:33.814Z] 18:26:33     INFO - GECKO(1834) | [Child 1846: Main Thread]: I/DocShellAndDOMWindowLeak ++DOMWINDOW == 1 (10c721e40) [pid = 1846] [serial = 1] [outer = 0]
[task 2021-03-19T18:26:33.814Z] 18:26:33     INFO - GECKO(1834) | [Child 1846: Main Thread]: I/DocShellAndDOMWindowLeak ++DOMWINDOW == 2 (110cf6400) [pid = 1846] [serial = 2] [outer = 10c721e40]
[task 2021-03-19T18:26:34.338Z] 18:26:34     INFO - GECKO(1834) | Saw state f0001 and status 0
[task 2021-03-19T18:26:35.714Z] 18:26:35     INFO - GECKO(1834) | [Child 1846, Main Thread] WARNING: NS_ENSURE_TRUE(info) failed: file /builds/worker/checkouts/gecko/extensions/permissions/PermissionDelegateHandler.cpp:348
[task 2021-03-19T18:26:35.715Z] 18:26:35     INFO - GECKO(1834) | [Child 1846: Main Thread]: I/DocShellAndDOMWindowLeak ++DOMWINDOW == 3 (110fc4000) [pid = 1846] [serial = 3] [outer = 10c721e40]
[task 2021-03-19T18:26:37.031Z] 18:26:37     INFO - GECKO(1834) | [Parent 1834: Main Thread]: I/DocShellAndDOMWindowLeak --DOCSHELL 11a9ed400 == 6 [pid = 1834] [id = 5] [url = about:blank]
[task 2021-03-19T18:26:37.031Z] 18:26:37     INFO - GECKO(1834) | [Parent 1834: Main Thread]: I/DocShellAndDOMWindowLeak --DOCSHELL 1039c6c00 == 5 [pid = 1834] [id = 4] [url = about:blank]
[task 2021-03-19T18:26:37.231Z] 18:26:37     INFO - GECKO(1834) | Saw state c0010 and status 0
[task 2021-03-19T18:26:37.233Z] 18:26:37     INFO - GECKO(1834) | Browser got expected state change http://example.com/
[task 2021-03-19T18:26:37.278Z] 18:26:37     INFO - GECKO(1834) | [Child 1842: Main Thread]: I/DocShellAndDOMWindowLeak ++DOCSHELL 11fbc3000 == 2 [pid = 1842] [id = 1]
[task 2021-03-19T18:26:37.278Z] 18:26:37     INFO - GECKO(1834) | [Child 1842: Main Thread]: I/DocShellAndDOMWindowLeak ++DOMWINDOW == 4 (10af21c80) [pid = 1842] [serial = 5] [outer = 0]
[task 2021-03-19T18:26:37.279Z] 18:26:37     INFO - GECKO(1834) | [Child 1842: Main Thread]: I/DocShellAndDOMWindowLeak ++DOMWINDOW == 5 (11fbc9800) [pid = 1842] [serial = 6] [outer = 10af21c80]
[task 2021-03-19T18:26:37.337Z] 18:26:37     INFO - GECKO(1834) | Waiting for browser load
[task 2021-03-19T18:26:37.337Z] 18:26:37     INFO - GECKO(1834) | Waiting for browser state change
[task 2021-03-19T18:26:37.954Z] 18:26:37     INFO - GECKO(1834) | Saw state f0001 and status 0
[task 2021-03-19T18:26:38.715Z] 18:26:38     INFO - GECKO(1834) | [Child 1842: Main Thread]: I/DocShellAndDOMWindowLeak --DOCSHELL 11fbc5000 == 1 [pid = 1842] [id = 0] [url = about:blank]
[task 2021-03-19T18:26:39.500Z] 18:26:39     INFO - GECKO(1834) | [Child 1842, Main Thread] WARNING: NS_ENSURE_TRUE(info) failed: file /builds/worker/checkouts/gecko/extensions/permissions/PermissionDelegateHandler.cpp:348
[task 2021-03-19T18:26:39.502Z] 18:26:39     INFO - GECKO(1834) | [Child 1842: Main Thread]: I/DocShellAndDOMWindowLeak ++DOMWINDOW == 6 (11ffcd000) [pid = 1842] [serial = 7] [outer = 10af21c80]
[task 2021-03-19T18:26:40.479Z] 18:26:40     INFO - GECKO(1834) | [Child 1842: Main Thread]: I/DocShellAndDOMWindowLeak --DOMWINDOW == 5 (10af21e40) [pid = 1842] [serial = 1] [outer = 0] [url = about:blank]
[task 2021-03-19T18:26:40.896Z] 18:26:40     INFO - GECKO(1834) | Saw state c0010 and status 0
[task 2021-03-19T18:26:40.897Z] 18:26:40     INFO - GECKO(1834) | Browser got expected state change http://example.com/
[task 2021-03-19T18:26:40.950Z] 18:26:40     INFO - GECKO(1834) | [1848, MainThread] WARNING: XPCOM objects created/destroyed from static ctor/dtor: file /builds/worker/checkouts/gecko/xpcom/base/nsTraceRefcnt.cpp:202
[task 2021-03-19T18:26:40.950Z] 18:26:40     INFO - GECKO(1834) | [1848, MainThread] WARNING: XPCOM objects created/destroyed from static ctor/dtor: file /builds/worker/checkouts/gecko/xpcom/base/nsTraceRefcnt.cpp:202
[task 2021-03-19T18:26:40.950Z] 18:26:40     INFO - GECKO(1834) | ### XPCOM_MEM_BLOAT_LOG defined -- logging bloat/leaks to /var/folders/lf/p5fbzdqs7m583jpg2_nhp12w000017/T/tmpOLvtJx.mozrunner/runtests_leaks_tab_pid1848.log
[task 2021-03-19T18:26:40.950Z] 18:26:40     INFO - GECKO(1834) | [1848, MainThread] WARNING: XPCOM objects created/destroyed from static ctor/dtor: file /builds/worker/checkouts/gecko/xpcom/base/nsTraceRefcnt.cpp:202
[task 2021-03-19T18:26:40.951Z] 18:26:40     INFO - GECKO(1834) | [1848, MainThread] WARNING: XPCOM objects created/destroyed from static ctor/dtor: file /builds/worker/checkouts/gecko/xpcom/base/nsTraceRefcnt.cpp:202
[task 2021-03-19T18:26:40.956Z] 18:26:40     INFO - GECKO(1834) | [1848, Main Thread] WARNING: XPCOM_MEM_BLOAT_LOG is set, disabling native allocations.: file /builds/worker/checkouts/gecko/tools/profiler/core/platform.cpp:251
[task 2021-03-19T18:26:40.962Z] 18:26:40     INFO - GECKO(1834) | [Child 1844: Main Thread]: I/DocShellAndDOMWindowLeak --DOMWINDOW == 2 (1113c4400) [pid = 1844] [serial = 2] [outer = 0] [url = about:blank]
<...>
[task 2021-03-19T18:28:52.760Z] 18:28:52     INFO - Buffered messages logged at 18:28:52
[task 2021-03-19T18:28:52.760Z] 18:28:52     INFO - Loaded https://example.com/.
[task 2021-03-19T18:28:52.761Z] 18:28:52     INFO - network.loadinfo.skip_type_assertion should not be accessed more than 40 times and was accessed 106 times.
[task 2021-03-19T18:28:52.761Z] 18:28:52     INFO - TEST-PASS | browser/base/content/test/performance/browser_preferences_usage.js | browser.zoom.full should be accessed at least 100 times. - 100 <= 102 - 
[task 2021-03-19T18:28:52.761Z] 18:28:52     INFO - TEST-PASS | browser/base/content/test/performance/browser_preferences_usage.js | browser.zoom.full should be accessed at most 110 times. - 102 <= 110 - 
[task 2021-03-19T18:28:52.761Z] 18:28:52     INFO - Buffered messages finished
[task 2021-03-19T18:28:52.761Z] 18:28:52     INFO - TEST-UNEXPECTED-FAIL | browser/base/content/test/performance/browser_preferences_usage.js | toolkit.telemetry.cachedClientID should not be accessed more than 40 times. - 57 <= 40 - JS frame :: chrome://mochitests/content/browser/browser/base/content/test/performance/browser_preferences_usage.js :: checkPrefGetters :: line 42
[task 2021-03-19T18:28:52.761Z] 18:28:52     INFO - Stack trace:
[task 2021-03-19T18:28:52.762Z] 18:28:52     INFO - chrome://mochitests/content/browser/browser/base/content/test/performance/browser_preferences_usage.js:checkPrefGetters:42
[task 2021-03-19T18:28:52.762Z] 18:28:52     INFO - chrome://mochitests/content/browser/browser/base/content/test/performance/browser_preferences_usage.js:navigate_around:282
[task 2021-03-19T18:28:52.762Z] 18:28:52     INFO - TEST-PASS | browser/base/content/test/performance/browser_preferences_usage.js | dom.ipc.keepProcessesAlive.web should not be accessed more than 40 times. - 7 <= 40 - 
[task 2021-03-19T18:28:52.762Z] 18:28:52     INFO - TEST-PASS | browser/base/content/test/performance/browser_preferences_usage.js | browser.startup.record should not be accessed more than 40 times. - 3 <= 40 - 
[task 2021-03-19T18:28:52.762Z] 18:28:52     INFO - TEST-PASS | browser/base/content/test/performance/browser_preferences_usage.js | app.update.lastUpdateTime.background-update-timer should not be accessed more than 40 times. - 3 <= 40 - 
[task 2021-03-19T18:28:52.763Z] 18:28:52     INFO - TEST-PASS | browser/base/content/test/performance/browser_preferences_usage.js | browser.proton.infobars.enabled should not be accessed more than 40 times. - 3 <= 40 - 
[task 2021-03-19T18:28:52.763Z] 18:28:52     INFO - TEST-PASS | browser/base/content/test/performance/browser_preferences_usage.js | app.update.lastUpdateTime.addon-background-update-timer should not be accessed more than 40 times. - 2 <= 40 - 
[task 2021-03-19T18:28:52.763Z] 18:28:52     INFO - TEST-PASS | browser/base/content/test/performance/browser_preferences_usage.js | browser.tabs.remote.separatedMozillaDomains should not be accessed more than 40 times. - 2 <= 40 - 
[task 2021-03-19T18:28:52.763Z] 18:28:52     INFO - TEST-PASS | browser/base/content/test/performance/browser_preferences_usage.js | app.update.lastUpdateTime.services-settings-poll-changes should not be accessed more than 40 times. - 2 <= 40 - 
[task 2021-03-19T18:28:52.763Z] 18:28:52     INFO - TEST-PASS | browser/base/content/test/performance/browser_preferences_usage.js | layout.css.dpi should not be accessed more than 40 times. - 2 <= 40 - 
[task 2021-03-19T18:28:52.763Z] 18:28:52     INFO - TEST-PASS | browser/base/content/test/performance/browser_preferences_usage.js | app.update.lastUpdateTime.search-engine-update-timer should not be accessed more than 40 times. - 2 <= 40 - 
[task 2021-03-19T18:28:52.764Z] 18:28:52     INFO - TEST-PASS | browser/base/content/test/performance/browser_preferences_usage.js | browser.tabs.remote.logSwitchTiming should not be accessed more than 40 times. - 2 <= 40 - 
[task 2021-03-19T18:28:52.764Z] 18:28:52     INFO - TEST-PASS | browser/base/content/test/performance/browser_preferences_usage.js | layout.reflow.dumpframebyframecounts should not be accessed more than 40 times. - 1 <= 40 - 
[task 2021-03-19T18:28:52.764Z] 18:28:52     INFO - TEST-PASS | browser/base/content/test/performance/browser_preferences_usage.js | app.update.log.file should not be accessed more than 40 times. - 1 <= 40 - 
[task 2021-03-19T18:28:52.764Z] 18:28:52     INFO - TEST-PASS | browser/base/content/test/performance/browser_preferences_usage.js | app.update.log should not be accessed more than 40 times. - 1 <= 40 - 
[task 2021-03-19T18:28:52.764Z] 18:28:52     INFO - TEST-PASS | browser/base/content/test/performance/browser_preferences_usage.js | datareporting.policy.dataSubmissionEnabled should not be accessed more than 40 times. - 1 <= 40 - 
[task 2021-03-19T18:28:52.765Z] 18:28:52     INFO - TEST-PASS | browser/base/content/test/performance/browser_preferences_usage.js | dom.ipc.tabs.disabled should not be accessed more than 40 times. - 1 <= 40 - 
[task 2021-03-19T18:28:52.765Z] 18:28:52     INFO - TEST-PASS | browser/base/content/test/performance/browser_preferences_usage.js | dom.ipc.multiOptOut should not be accessed more than 40 times. - 1 <= 40 - 
[task 2021-03-19T18:28:52.765Z] 18:28:52     INFO - TEST-PASS | browser/base/content/test/performance/browser_preferences_usage.js | nglayout.debug.paint_flashing should not be accessed more than 40 times. - 1 <= 40 - 
[task 2021-03-19T18:28:52.770Z] 18:28:52     INFO - TEST-PASS | browser/base/content/test/performance/browser_preferences_usage.js | bidi.numeral should not be accessed more than 40 times. - 1 <= 40 - 
[task 2021-03-19T18:28:52.770Z] 18:28:52     INFO - TEST-PASS | browser/base/content/test/performance/browser_preferences_usage.js | bidi.texttype should not be accessed more than 40 times. - 1 <= 40 - 
[task 2021-03-19T18:28:52.770Z] 18:28:52     INFO - TEST-PASS | browser/base/content/test/performance/browser_preferences_usage.js | layout.throttled_frame_rate should not be accessed more than 40 times. - 1 <= 40 - 
[task 2021-03-19T18:28:52.771Z] 18:28:52     INFO - TEST-PASS | browser/base/content/test/performance/browser_preferences_usage.js | browser.search.update.interval should not be accessed more than 40 times. - 1 <= 40 - 
[task 2021-03-19T18:28:52.771Z] 18:28:52     INFO - TEST-PASS | browser/base/content/test/performance/browser_preferences_usage.js | app.update.altUpdateDirPath should not be accessed more than 40 times. - 1 <= 40 - 
[task 2021-03-19T18:28:52.771Z] 18:28:52     INFO - TEST-PASS | browser/base/content/test/performance/browser_preferences_usage.js | browser.newtabpage.activity-stream.improvesearch.topSiteSearchShortcuts should not be accessed more than 40 times. - 1 <= 40 - 
[task 2021-03-19T18:28:52.771Z] 18:28:52     INFO - TEST-PASS | browser/base/content/test/performance/browser_preferences_usage.js | layout.scrollbar.side should not be accessed more than 40 times. - 1 <= 40 - 
[task 2021-03-19T18:28:52.771Z] 18:28:52     INFO - TEST-PASS | browser/base/content/test/performance/browser_preferences_usage.js | dom.ipc.processCount should not be accessed more than 40 times. - 1 <= 40 - 
[task 2021-03-19T18:28:52.771Z] 18:28:52     INFO - TEST-PASS | browser/base/content/test/performance/browser_preferences_usage.js | datareporting.policy.dataSubmissionPolicyNotifiedTime should not be accessed more than 40 times. - 1 <= 40 - 
[task 2021-03-19T18:28:52.771Z] 18:28:52     INFO - TEST-PASS | browser/base/content/test/performance/browser_preferences_usage.js | browser.tabs.insertAfterCurrent should not be accessed more than 40 times. - 1 <= 40 - 
[task 2021-03-19T18:28:52.772Z] 18:28:52     INFO - TEST-PASS | browser/base/content/test/performance/browser_preferences_usage.js | browser.display.auto_quality_min_font_size should not be accessed more than 40 times. - 1 <= 40 - 
[task 2021-03-19T18:28:52.772Z] 18:28:52     INFO - TEST-PASS | browser/base/content/test/performance/browser_preferences_usage.js | layout.reflow.showframecounts should not be accessed more than 40 times. - 1 <= 40 - 
[task 2021-03-19T18:28:52.772Z] 18:28:52     INFO - TEST-PASS | browser/base/content/test/performance/browser_preferences_usage.js | layout.visibility.min-recompute-interval-ms should not be accessed more than 40 times. - 1 <= 40 - 
[task 2021-03-19T18:28:52.772Z] 18:28:52     INFO - TEST-PASS | browser/base/content/test/performance/browser_preferences_usage.js | datareporting.policy.dataSubmissionPolicyBypassNotification should not be accessed more than 40 times. - 1 <= 40 - 
[task 2021-03-19T18:28:52.772Z] 18:28:52     INFO - TEST-PASS | browser/base/content/test/performance/browser_preferences_usage.js | bidi.direction should not be accessed more than 40 times. - 1 <= 40 - 
[task 2021-03-19T18:28:52.772Z] 18:28:52     INFO - TEST-PASS | browser/base/content/test/performance/browser_preferences_usage.js | dom.send_after_paint_to_content should not be accessed more than 40 times. - 1 <= 40 - 
[task 2021-03-19T18:28:52.772Z] 18:28:52     INFO - TEST-PASS | browser/base/content/test/performance/browser_preferences_usage.js | image.animation_mode should not be accessed more than 40 times. - 1 <= 40 - 
[task 2021-03-19T18:28:52.773Z] 18:28:52     INFO - TEST-PASS | browser/base/content/test/performance/browser_preferences_usage.js | nglayout.initialpaint.delay should not be accessed more than 40 times. - 1 <= 40 - 
[task 2021-03-19T18:28:52.773Z] 18:28:52     INFO - TEST-PASS | browser/base/content/test/performance/browser_preferences_usage.js | services.settings.poll_interval should not be accessed more than 40 times. - 1 <= 40 - 
[task 2021-03-19T18:28:52.773Z] 18:28:52     INFO - TEST-PASS | browser/base/content/test/performance/browser_preferences_usage.js | app.update.disabledForTesting should not be accessed more than 40 times. - 1 <= 40 - 
[task 2021-03-19T18:28:52.773Z] 18:28:52     INFO - TEST-PASS | browser/base/content/test/performance/browser_preferences_usage.js | app.update.interval should not be accessed more than 40 times. - 1 <= 40 - 
[task 2021-03-19T18:28:52.773Z] 18:28:52     INFO - TEST-PASS | browser/base/content/test/performance/browser_preferences_usage.js | gfx.missing_fonts.notify should not be accessed more than 40 times. - 1 <= 40 - 
[task 2021-03-19T18:28:52.773Z] 18:28:52     INFO - TEST-PASS | browser/base/content/test/performance/browser_preferences_usage.js | extensions.update.interval should not be accessed more than 40 times. - 1 <= 40 - 
[task 2021-03-19T18:28:52.773Z] 18:28:52     INFO - TEST-PASS | browser/base/content/test/performance/browser_preferences_usage.js | layout.reflow.dumpframecounts should not be accessed more than 40 times. - 1 <= 40 - 
[task 2021-03-19T18:28:52.773Z] 18:28:52     INFO - TEST-PASS | browser/base/content/test/performance/browser_preferences_usage.js | browser.topsites.useRemoteSetting should not be accessed more than 40 times. - 1 <= 40 - 
[task 2021-03-19T18:28:52.774Z] 18:28:52     INFO - TEST-PASS | browser/base/content/test/performance/browser_preferences_usage.js | Should have accessed all known problematic prefs. Remaining:  - 
[task 2021-03-19T18:28:52.774Z] 18:28:52     INFO - Leaving test bound navigate_around
[task 2021-03-19T18:28:52.774Z] 18:28:52     INFO - GECKO(1834) | [Parent 1834, Main Thread] WARNING: WebProgress Ignored: BrowsingContext is null or discarded: file /builds/worker/checkouts/gecko/dom/ipc/BrowserParent.cpp:2861
[task 2021-03-19T18:28:52.804Z] 18:28:52     INFO - Not taking screenshot here: see the one that was previously logged
[task 2021-03-19T18:28:52.805Z] 18:28:52     INFO - TEST-UNEXPECTED-FAIL | browser/base/content/test/performance/browser_preferences_usage.js | This test exceeded the timeout threshold. It should be rewritten or split up. If that's not possible, use requestLongerTimeout(N), but only as a last resort. - 
[task 2021-03-19T18:28:52.805Z] 18:28:52     INFO - GECKO(1834) | MEMORY STAT vsizeMaxContiguous not supported in this build configuration.
[task 2021-03-19T18:28:52.805Z] 18:28:52     INFO - GECKO(1834) | MEMORY STAT | vsize 7741MB | residentFast 351MB | heapAllocated 137MB
[task 2021-03-19T18:28:52.805Z] 18:28:52     INFO - TEST-OK | browser/base/content/test/performance/browser_preferences_usage.js | took 140495ms
[task 2021-03-19T18:28:52.815Z] 18:28:52     INFO - GECKO(1834) | [Child 1842: Main Thread]: I/DocShellAndDOMWindowLeak ++DOCSHELL 10af12800 == 1 [pid = 1842] [id = 3]
[task 2021-03-19T18:28:52.815Z] 18:28:52     INFO - GECKO(1834) | [Child 1842: Main Thread]: I/DocShellAndDOMWindowLeak ++DOMWINDOW == 1 (10af21c80) [pid = 1842] [serial = 11] [outer = 0]
[task 2021-03-19T18:28:52.815Z] 18:28:52     INFO - GECKO(1834) | [Child 1842: Main Thread]: I/DocShellAndDOMWindowLeak ++DOMWINDOW == 2 (11fbc2800) [pid = 1842] [serial = 12] [outer = 10af21c80]
[task 2021-03-19T18:28:52.875Z] 18:28:52     INFO - checking window state
[task 2021-03-19T18:28:53.008Z] 18:28:53     INFO - TEST-START | browser/base/content/test/performance/browser_preferences_usage.js```