Bug: Intermittent browser/components/newtab/test/browser/browser_aboutwelcome_multistage.js | Uncaught exception - at /components/newtab/test/browser/browser_aboutwelcome_multistage.js:435 - TypeError: can't access property "event", args[1] is undefined
Status: RESOLVED
Priority: P5
Resolution: FIXED
Created: 2021-04-28 22:30:58+00:00
Resolved: 2021-06-03 10:30:37+00:00

**Filed by:** malexandru [at] mozilla.com
**Parsed log:** https://treeherder.mozilla.org/logviewer?job_id=338071373&repo=autoland
**Full log:** https://firefox-ci-tc.services.mozilla.com/api/queue/v1/task/WcWqb0HUQHaNXcBPmLCF1w/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/WcWqb0HUQHaNXcBPmLCF1w/runs/0/artifacts/public/logs/live_backing.log&only_show_unexpected=1

---
```
[task 2021-04-28T20:44:49.134Z] 20:44:49     INFO - TEST-START | browser/components/newtab/test/browser/browser_aboutwelcome_multistage.js
[task 2021-04-28T20:44:49.210Z] 20:44:49     INFO - GECKO(1837) | [Child 2010: Main Thread]: I/DocShellAndDOMWindowLeak ++DOCSHELL 7f8cfec93800 == 1 [pid = 2010] [id = 0]
[task 2021-04-28T20:44:49.210Z] 20:44:49     INFO - GECKO(1837) | [Child 2010: Main Thread]: I/DocShellAndDOMWindowLeak ++DOMWINDOW == 1 (7f8d15364200) [pid = 2010] [serial = 1] [outer = 0]
[task 2021-04-28T20:44:49.211Z] 20:44:49     INFO - GECKO(1837) | [Child 2010: Main Thread]: I/DocShellAndDOMWindowLeak ++DOMWINDOW == 2 (7f8cfec94800) [pid = 2010] [serial = 2] [outer = 7f8d15364200]
[task 2021-04-28T20:44:49.570Z] 20:44:49     INFO - GECKO(1837) | console.debug: ExperimentManager:
[task 2021-04-28T20:44:49.570Z] 20:44:49     INFO - GECKO(1837) |   New experiment started: mochitest-1-aboutwelcome, mochitest-1-aboutwelcome
[task 2021-04-28T20:44:49.586Z] 20:44:49     INFO - GECKO(1837) | [Child 1981: Main Thread]: I/DocShellAndDOMWindowLeak ++DOCSHELL 7f67e27a1000 == 2 [pid = 1981] [id = 1]
[task 2021-04-28T20:44:49.586Z] 20:44:49     INFO - GECKO(1837) | [Child 1981: Main Thread]: I/DocShellAndDOMWindowLeak ++DOMWINDOW == 4 (7f67e9b2b3c0) [pid = 1981] [serial = 4] [outer = 0]
[task 2021-04-28T20:44:49.586Z] 20:44:49     INFO - GECKO(1837) | [Child 1981: Main Thread]: I/DocShellAndDOMWindowLeak ++DOMWINDOW == 5 (7f67e27a2000) [pid = 1981] [serial = 5] [outer = 7f67e9b2b3c0]
[task 2021-04-28T20:44:49.826Z] 20:44:49     INFO - GECKO(1837) | [Child 1981, Main Thread] WARNING: Scrolled rect smaller than scrollport?: file /builds/worker/checkouts/gecko/layout/generic/nsGfxScrollFrame.cpp:7064
[task 2021-04-28T20:44:49.903Z] 20:44:49     INFO - GECKO(1837) | [Child 1981: Main Thread]: I/DocShellAndDOMWindowLeak ++DOMWINDOW == 6 (7f67e0927400) [pid = 1981] [serial = 6] [outer = 7f67e9b2b3c0]
[task 2021-04-28T20:44:49.919Z] 20:44:49     INFO - GECKO(1837) | console.debug: AboutWelcomeChild:
[task 2021-04-28T20:44:49.923Z] 20:44:49     INFO - GECKO(1837) |   Received page event DOMWindowCreated
[task 2021-04-28T20:44:49.931Z] 20:44:49     INFO - GECKO(1837) | console.debug: AboutWelcomeChild:
[task 2021-04-28T20:44:49.931Z] 20:44:49     INFO - GECKO(1837) |   onLocationChange handled: [object Window]
[task 2021-04-28T20:44:49.935Z] 20:44:49     INFO - GECKO(1837) | console.debug: AboutWelcomeParent:
[task 2021-04-28T20:44:49.935Z] 20:44:49     INFO - GECKO(1837) |   Received content event: AWPage:LOCATION_CHANGED
[task 2021-04-28T20:44:50.036Z] 20:44:50     INFO - GECKO(1837) | ### XPCOM_MEM_BLOAT_LOG defined -- logging bloat/leaks to /tmp/tmpXyqhnh.mozrunner/runtests_leaks_tab_pid2038.log
[task 2021-04-28T20:44:50.037Z] 20:44:50     INFO - GECKO(1837) | [2038, Main Thread] WARNING: XPCOM_MEM_BLOAT_LOG is set, disabling native allocations.: file /builds/worker/checkouts/gecko/tools/profiler/core/platform.cpp:254
[task 2021-04-28T20:44:50.139Z] 20:44:50     INFO - GECKO(1837) | [Child 2038, Main Thread] WARNING: could not set real-time limit in CubebUtils::InitLibrary: file /builds/worker/checkouts/gecko/dom/media/CubebUtils.cpp:619
[task 2021-04-28T20:44:50.489Z] 20:44:50     INFO - GECKO(1837) | [Child 1981, Main Thread] WARNING: Scrolled rect smaller than scrollport?: file /builds/worker/checkouts/gecko/layout/generic/nsGfxScrollFrame.cpp:7064
[task 2021-04-28T20:44:50.763Z] 20:44:50     INFO - GECKO(1837) | console.debug: ExperimentManager:
[task 2021-04-28T20:44:50.764Z] 20:44:50     INFO - GECKO(1837) |   Experiment unenrolled: mochitest-1-aboutwelcome
[task 2021-04-28T20:44:50.779Z] 20:44:50     INFO - GECKO(1837) | console.debug: ExperimentManager:
[task 2021-04-28T20:44:50.780Z] 20:44:50     INFO - GECKO(1837) |   New experiment started: mochitest-aboutwelcome, mochitest-aboutwelcome-branch
[task 2021-04-28T20:44:50.796Z] 20:44:50     INFO - GECKO(1837) | [Child 1981: Main Thread]: I/DocShellAndDOMWindowLeak ++DOCSHELL 7f67e0755800 == 3 [pid = 1981] [id = 2]
[task 2021-04-28T20:44:50.797Z] 20:44:50     INFO - GECKO(1837) | [Child 1981: Main Thread]: I/DocShellAndDOMWindowLeak ++DOMWINDOW == 7 (7f6800264ac0) [pid = 1981] [serial = 7] [outer = 0]
[task 2021-04-28T20:44:50.798Z] 20:44:50     INFO - GECKO(1837) | [Child 1981: Main Thread]: I/DocShellAndDOMWindowLeak ++DOMWINDOW == 8 (7f67e0756800) [pid = 1981] [serial = 8] [outer = 7f6800264ac0]
[task 2021-04-28T20:44:50.879Z] 20:44:50     INFO - GECKO(1837) | [Child 1981: Main Thread]: I/DocShellAndDOMWindowLeak ++DOMWINDOW == 9 (7f67e27a2400) [pid = 1981] [serial = 9] [outer = 7f6800264ac0]
[task 2021-04-28T20:44:50.903Z] 20:44:50     INFO - GECKO(1837) | console.debug: AboutWelcomeChild:
[task 2021-04-28T20:44:50.906Z] 20:44:50     INFO - GECKO(1837) |   Received page event DOMWindowCreated
[task 2021-04-28T20:44:50.908Z] 20:44:50     INFO - GECKO(1837) | console.debug: AboutWelcomeChild:
[task 2021-04-28T20:44:50.914Z] 20:44:50     INFO - GECKO(1837) |   onLocationChange handled: [object Window]
[task 2021-04-28T20:44:50.920Z] 20:44:50     INFO - GECKO(1837) | console.debug: AboutWelcomeParent:
[task 2021-04-28T20:44:50.921Z] 20:44:50     INFO - GECKO(1837) |   Received content event: AWPage:LOCATION_CHANGED
[task 2021-04-28T20:44:51.013Z] 20:44:51     INFO - GECKO(1837) | console.debug: AboutWelcomeChild:
[task 2021-04-28T20:44:51.013Z] 20:44:51     INFO - GECKO(1837) |   Loading about:welcome with experiment: mochitest-aboutwelcome
[task 2021-04-28T20:44:51.061Z] 20:44:51     INFO - GECKO(1837) | console.debug: AboutWelcomeParent:
[task 2021-04-28T20:44:51.061Z] 20:44:51     INFO - GECKO(1837) |   Received content event: AWPage:FXA_METRICS_FLOW_URI
[task 2021-04-28T20:44:51.065Z] 20:44:51     INFO - GECKO(1837) | console.debug: AboutWelcomeParent:
[task 2021-04-28T20:44:51.070Z] 20:44:51     INFO - GECKO(1837) |   Received content event: AWPage:SET_WELCOME_MESSAGE_SEEN
[task 2021-04-28T20:44:51.074Z] 20:44:51     INFO - GECKO(1837) | console.debug: AboutWelcomeParent:
[task 2021-04-28T20:44:51.090Z] 20:44:51     INFO - GECKO(1837) |   Received content event: AWPage:TELEMETRY_EVENT
[task 2021-04-28T20:44:51.094Z] 20:44:51     INFO - GECKO(1837) | console.debug: AboutWelcomeParent:
[task 2021-04-28T20:44:51.096Z] 20:44:51     INFO - GECKO(1837) |   Received content event: AWPage:GET_REGION
[task 2021-04-28T20:44:51.097Z] 20:44:51     INFO - GECKO(1837) | console.debug: AboutWelcomeParent:
[task 2021-04-28T20:44:51.104Z] 20:44:51     INFO - GECKO(1837) |   Received content event: AWPage:GET_SELECTED_THEME
[task 2021-04-28T20:44:51.241Z] 20:44:51     INFO - GECKO(1837) | console.debug: AboutWelcomeParent:
[task 2021-04-28T20:44:51.257Z] 20:44:51     INFO - GECKO(1837) |   Received content event: AWPage:TELEMETRY_EVENT
[task 2021-04-28T20:44:51.272Z] 20:44:51     INFO - GECKO(1837) | console.debug: AboutWelcomeParent:
[task 2021-04-28T20:44:51.274Z] 20:44:51     INFO - GECKO(1837) |   Received content event: AWPage:IMPORTABLE_SITES
[task 2021-04-28T20:44:51.328Z] 20:44:51     INFO - GECKO(1837) | console.debug: AboutWelcomeParent:
[task 2021-04-28T20:44:51.330Z] 20:44:51     INFO - GECKO(1837) |   Received content event: AWPage:TELEMETRY_EVENT
[task 2021-04-28T20:44:52.321Z] 20:44:52     INFO - GECKO(1837) | [Parent 1837: Main Thread]: I/DocShellAndDOMWindowLeak --DOCSHELL 7ff4566d8800 == 6 [pid = 1837] [id = 4] [url = about:blank]
[task 2021-04-28T20:44:52.321Z] 20:44:52     INFO - GECKO(1837) | [Parent 1837: Main Thread]: I/DocShellAndDOMWindowLeak --DOCSHELL 7ff4566ddc00 == 5 [pid = 1837] [id = 5] [url = about:blank]
[task 2021-04-28T20:44:52.578Z] 20:44:52     INFO - GECKO(1837) | [Parent 1837: Main Thread]: I/DocShellAndDOMWindowLeak --DOMWINDOW == 14 (7ff45689dac0) [pid = 1837] [serial = 11] [outer = 0] [url = about:blank]
[task 2021-04-28T20:44:52.578Z] 20:44:52     INFO - GECKO(1837) | [Parent 1837: Main Thread]: I/DocShellAndDOMWindowLeak --DOMWINDOW == 13 (7ff45f2b2e40) [pid = 1837] [serial = 10] [outer = 0] [url = about:blank]
[task 2021-04-28T20:44:52.667Z] 20:44:52     INFO - GECKO(1837) | console.debug: AboutWelcomeParent:
[task 2021-04-28T20:44:52.667Z] 20:44:52     INFO - GECKO(1837) |   Received content event: AWPage:TELEMETRY_EVENT
[task 2021-04-28T20:44:52.688Z] 20:44:52     INFO - TEST-INFO | started process screentopng
[task 2021-04-28T20:44:53.056Z] 20:44:53     INFO - TEST-INFO | screentopng: exit 0
[task 2021-04-28T20:44:53.057Z] 20:44:53     INFO - Buffered messages logged at 20:44:49
[task 2021-04-28T20:44:53.057Z] 20:44:53     INFO - TEST-PASS | browser/components/newtab/test/browser/browser_aboutwelcome_multistage.js | Sanity check the temporary file doesn't exist. - true == true - 
[task 2021-04-28T20:44:53.058Z] 20:44:53     INFO - Entering test bound setup
[task 2021-04-28T20:44:53.059Z] 20:44:53     INFO - Leaving test bound setup
[task 2021-04-28T20:44:53.059Z] 20:44:53     INFO - Entering test bound test_multistage_zeroOnboarding_experimentAPI
[task 2021-04-28T20:44:53.059Z] 20:44:53     INFO - Buffered messages logged at 20:44:50
[task 2021-04-28T20:44:53.060Z] 20:44:53     INFO - TEST-PASS | browser/components/newtab/test/browser/browser_aboutwelcome_multistage.js | Should not render div.onboardingContainer in Opens new tab - true == true - 
[task 2021-04-28T20:44:53.060Z] 20:44:53     INFO - TEST-PASS | browser/components/newtab/test/browser/browser_aboutwelcome_multistage.js | Should not render main.AW_STEP1 in Opens new tab - true == true - 
[task 2021-04-28T20:44:53.060Z] 20:44:53     INFO - TEST-PASS | browser/components/newtab/test/browser/browser_aboutwelcome_multistage.js | Navigated to a welcome screen - "about:welcome" == "about:welcome" - 
[task 2021-04-28T20:44:53.061Z] 20:44:53     INFO - Leaving test bound test_multistage_zeroOnboarding_experimentAPI
[task 2021-04-28T20:44:53.061Z] 20:44:53     INFO - Entering test bound test_multistage_aboutwelcome_experimentAPI
[task 2021-04-28T20:44:53.063Z] 20:44:53     INFO - Buffered messages logged at 20:44:51
[task 2021-04-28T20:44:53.063Z] 20:44:53     INFO - Console message: [JavaScript Warning: "Layout was forced before the page was fully loaded. If stylesheets are not yet loaded this may cause a flash of unstyled content." {file: "resource://activity-stream/aboutwelcome/aboutwelcome.bundle.js" line: 971}]
[task 2021-04-28T20:44:53.063Z] 20:44:53     INFO - Console message: [JavaScript Error: "can't access property "createInstance", Cc[("@mozilla.org/profile/migrator;1?app=browser&type=" + aKey)] is undefined" {file: "resource:///modules/MigrationUtils.jsm" line: 792}]
[task 2021-04-28T20:44:53.063Z] 20:44:53     INFO - MU_getMigrator@resource:///modules/MigrationUtils.jsm:792:1
[task 2021-04-28T20:44:53.064Z] 20:44:53     INFO - getImportableSites@resource:///actors/AboutWelcomeParent.jsm:63:43
[task 2021-04-28T20:44:53.064Z] 20:44:53     INFO - 
[task 2021-04-28T20:44:53.064Z] 20:44:53     INFO - Buffered messages logged at 20:44:52
[task 2021-04-28T20:44:53.064Z] 20:44:53     INFO - TEST-PASS | browser/components/newtab/test/browser/browser_aboutwelcome_multistage.js | Should not render main.AW_STEP2 in multistage step 1 - true == true - 
[task 2021-04-28T20:44:53.065Z] 20:44:53     INFO - TEST-PASS | browser/components/newtab/test/browser/browser_aboutwelcome_multistage.js | Should not render main.AW_STEP3 in multistage step 1 - true == true - 
[task 2021-04-28T20:44:53.065Z] 20:44:53     INFO - TEST-PASS | browser/components/newtab/test/browser/browser_aboutwelcome_multistage.js | Should not render div.tiles-container.info in multistage step 1 - true == true - 
[task 2021-04-28T20:44:53.065Z] 20:44:53     INFO - TEST-PASS | browser/components/newtab/test/browser/browser_aboutwelcome_multistage.js | Navigated to a welcome screen - "about:welcome" == "about:welcome" - 
[task 2021-04-28T20:44:53.065Z] 20:44:53     INFO - Buffered messages finished
[task 2021-04-28T20:44:53.067Z] 20:44:53     INFO - TEST-UNEXPECTED-FAIL | browser/components/newtab/test/browser/browser_aboutwelcome_multistage.js | Uncaught exception - at chrome://mochitests/content/browser/browser/components/newtab/test/browser/browser_aboutwelcome_multistage.js:435 - TypeError: can't access property "event", args[1] is undefined
[task 2021-04-28T20:44:53.067Z] 20:44:53     INFO - Stack trace:
[task 2021-04-28T20:44:53.067Z] 20:44:53     INFO - test_multistage_aboutwelcome_experimentAPI/<@chrome://mochitests/content/browser/browser/components/newtab/test/browser/browser_aboutwelcome_multistage.js:435:11
[task 2021-04-28T20:44:53.067Z] 20:44:53     INFO - test_multistage_aboutwelcome_experimentAPI@chrome://mochitests/content/browser/browser/components/newtab/test/browser/browser_aboutwelcome_multistage.js:433:47
[task 2021-04-28T20:44:53.068Z] 20:44:53     INFO - Leaving test bound test_multistage_aboutwelcome_experimentAPI
[task 2021-04-28T20:44:53.068Z] 20:44:53     INFO - Entering test bound test_Multistage_About_Welcome_branches
[task 2021-04-28T20:44:53.070Z] 20:44:53     INFO - GECKO(1837) | console.debug: AboutWelcomeParent:
[task 2021-04-28T20:44:53.070Z] 20:44:53     INFO - GECKO(1837) |   Received content event: AWPage:TELEMETRY_EVENT
<...>
[task 2021-04-28T20:44:58.908Z] 20:44:58     INFO - GECKO(1837) | console.debug: AboutWelcomeParent:
[task 2021-04-28T20:44:58.912Z] 20:44:58     INFO - GECKO(1837) |   Received content event: AWPage:TELEMETRY_EVENT
[task 2021-04-28T20:44:59.114Z] 20:44:59     INFO - TEST-PASS | browser/components/newtab/test/browser/browser_aboutwelcome_multistage.js | 1 Stub was called - 
[task 2021-04-28T20:44:59.114Z] 20:44:59     INFO - Call #0: AWPage:TELEMETRY_EVENT {"event":"CLICK_BUTTON","event_context":{"source":"primary_button","page":"about:welcome"},"message_id":"MY-MOCHITEST-EXPERIMENT_AW_STEP1"}
[task 2021-04-28T20:44:59.123Z] 20:44:59     INFO - TEST-PASS | browser/components/newtab/test/browser/browser_aboutwelcome_multistage.js | send telemetry event - "AWPage:TELEMETRY_EVENT" == "AWPage:TELEMETRY_EVENT" - 
[task 2021-04-28T20:44:59.124Z] 20:44:59     INFO - TEST-PASS | browser/components/newtab/test/browser/browser_aboutwelcome_multistage.js | click button event recorded in telemetry - "CLICK_BUTTON" == "CLICK_BUTTON" - 
[task 2021-04-28T20:44:59.125Z] 20:44:59     INFO - TEST-PASS | browser/components/newtab/test/browser/browser_aboutwelcome_multistage.js | primary button click source recorded in telemetry - "primary_button" == "primary_button" - 
[task 2021-04-28T20:44:59.133Z] 20:44:59     INFO - Not taking screenshot here: see the one that was previously logged
[task 2021-04-28T20:44:59.133Z] 20:44:59     INFO - TEST-UNEXPECTED-FAIL | browser/components/newtab/test/browser/browser_aboutwelcome_multistage.js | MessageId sent in click event telemetry - "MY-MOCHITEST-EXPERIMENT_AW_STEP1" == "DEFAULT_ABOUTWELCOME_AW_STEP1" - JS frame :: chrome://mochitests/content/browser/browser/components/newtab/test/browser/browser_aboutwelcome_multistage.js :: test_AWMultistage_Primary_Action :: line 739
[task 2021-04-28T20:44:59.133Z] 20:44:59     INFO - Stack trace:
[task 2021-04-28T20:44:59.133Z] 20:44:59     INFO - chrome://mochitests/content/browser/browser/components/newtab/test/browser/browser_aboutwelcome_multistage.js:test_AWMultistage_Primary_Action:739
[task 2021-04-28T20:44:59.133Z] 20:44:59     INFO - Leaving test bound test_AWMultistage_Primary_Action
[task 2021-04-28T20:44:59.133Z] 20:44:59     INFO - GECKO(1837) | console.debug: AboutWelcomeChild:
[task 2021-04-28T20:44:59.134Z] 20:44:59     INFO - Entering test bound test_AWMultistage_Secondary_Open_URL_Action
[task 2021-04-28T20:44:59.135Z] 20:44:59     INFO - GECKO(1837) |   onLocationChange handled: [object Window]
[task 2021-04-28T20:44:59.144Z] 20:44:59     INFO - GECKO(1837) | [Parent 1837, Main Thread] WARNING: NS_ENSURE_TRUE(aPrefName) failed: file /builds/worker/checkouts/gecko/modules/libpref/Preferences.cpp:2466
[task 2021-04-28T20:44:59.145Z] 20:44:59     INFO - GECKO(1837) | [Parent 1837, Main Thread] WARNING: NS_ENSURE_TRUE(aPrefName) failed: file /builds/worker/checkouts/gecko/modules/libpref/Preferences.cpp:2466
[task 2021-04-28T20:44:59.163Z] 20:44:59     INFO - GECKO(1837) | console.debug: ExperimentManager:
[task 2021-04-28T20:44:59.164Z] 20:44:59     INFO - GECKO(1837) |   Experiment unenrolled: mochitest-aboutwelcome
[task 2021-04-28T20:44:59.197Z] 20:44:59     INFO - GECKO(1837) | [Child 1981: Main Thread]: I/DocShellAndDOMWindowLeak ++DOCSHELL 7f67dfe87400 == 7 [pid = 1981] [id = 6]
[task 2021-04-28T20:44:59.197Z] 20:44:59     INFO - GECKO(1837) | [Child 1981: Main Thread]: I/DocShellAndDOMWindowLeak ++DOMWINDOW == 20 (7f67e9b30200) [pid = 1981] [serial = 20] [outer = 0]
[task 2021-04-28T20:44:59.204Z] 20:44:59     INFO - GECKO(1837) | [Child 1981: Main Thread]: I/DocShellAndDOMWindowLeak ++DOMWINDOW == 21 (7f67dfe89400) [pid = 1981] [serial = 21] [outer = 7f67e9b30200]
[task 2021-04-28T20:44:59.342Z] 20:44:59     INFO - GECKO(1837) | [Child 1981: Main Thread]: I/DocShellAndDOMWindowLeak ++DOMWINDOW == 22 (7f67e24ab800) [pid = 1981] [serial = 22] [outer = 7f67e9b30200]
[task 2021-04-28T20:44:59.369Z] 20:44:59     INFO - GECKO(1837) | console.debug: AboutWelcomeChild:
[task 2021-04-28T20:44:59.370Z] 20:44:59     INFO - GECKO(1837) |   Received page event DOMWindowCreated
[task 2021-04-28T20:44:59.373Z] 20:44:59     INFO - GECKO(1837) | console.debug: AboutWelcomeChild:
[task 2021-04-28T20:44:59.375Z] 20:44:59     INFO - GECKO(1837) |   onLocationChange handled: [object Window]
[task 2021-04-28T20:44:59.381Z] 20:44:59     INFO - GECKO(1837) | console.debug: AboutWelcomeParent:
[task 2021-04-28T20:44:59.383Z] 20:44:59     INFO - GECKO(1837) |   Received content event: AWPage:LOCATION_CHANGED
[task 2021-04-28T20:44:59.474Z] 20:44:59     INFO - GECKO(1837) | console.debug: AboutWelcomeChild:
[task 2021-04-28T20:44:59.474Z] 20:44:59     INFO - GECKO(1837) |   Loading about:welcome without experiment
[task 2021-04-28T20:44:59.476Z] 20:44:59     INFO - GECKO(1837) | console.debug: AboutWelcomeParent:
[task 2021-04-28T20:44:59.476Z] 20:44:59     INFO - GECKO(1837) |   Received content event: AWPage:GET_ATTRIBUTION_DATA
[task 2021-04-28T20:44:59.492Z] 20:44:59     INFO - GECKO(1837) | console.debug: AboutWelcomeChild:
[task 2021-04-28T20:44:59.492Z] 20:44:59     INFO - GECKO(1837) |   Loading about:welcome with default data and UA attribution
[task 2021-04-28T20:44:59.588Z] 20:44:59     INFO - GECKO(1837) | console.debug: AboutWelcomeParent:
[task 2021-04-28T20:44:59.589Z] 20:44:59     INFO - GECKO(1837) |   Received content event: AWPage:FXA_METRICS_FLOW_URI
[task 2021-04-28T20:44:59.590Z] 20:44:59     INFO - GECKO(1837) | console.debug: AboutWelcomeParent:
[task 2021-04-28T20:44:59.591Z] 20:44:59     INFO - GECKO(1837) |   Received content event: AWPage:TELEMETRY_EVENT
[task 2021-04-28T20:44:59.591Z] 20:44:59     INFO - GECKO(1837) | console.debug: AboutWelcomeParent:
[task 2021-04-28T20:44:59.592Z] 20:44:59     INFO - GECKO(1837) |   Received content event: AWPage:SET_WELCOME_MESSAGE_SEEN
[task 2021-04-28T20:44:59.632Z] 20:44:59     INFO - GECKO(1837) | console.debug: AboutWelcomeParent:
[task 2021-04-28T20:44:59.634Z] 20:44:59     INFO - GECKO(1837) |   Received content event: AWPage:TELEMETRY_EVENT
[task 2021-04-28T20:44:59.790Z] 20:44:59     INFO - TEST-PASS | browser/components/newtab/test/browser/browser_aboutwelcome_multistage.js | 5 Stub called twice to handle FxA open URL and Telemetry - 
[task 2021-04-28T20:44:59.791Z] 20:44:59     INFO - Call #0: AWPage:GET_REGION undefined```