Here's a snippet of the test run, with the exception that I think is causing the problem here (though I'm not entirely sure):
```
0:12.47 INFO Entering test bound testPrintMultiple
[...] 0:13.65 PASS There is one print dialog -
0:13.66 PASS The dialog is visible -
0:13.66 PASS The URL of the browser is the one we expect -
0:13.66 GECKO(3580) console.log: ***DHOLBERT _openTabModalPrint: calling getPreviewBrowser
0:13.66 GECKO(3580) console.log: ***DHOLBERT getPreviewBrowser: Entering function
0:13.66 GECKO(3580) console.log: ***DHOLBERT getPreviewBrowser: browser is non-null! returning it.
0:13.66 GECKO(3580) console.log: ***DHOLBERT _openTabModalPrint: rejecting in previewBrowser case
0:13.66 INFO Console message: [JavaScript Error: "undefined" {file: "chrome://global/content/printUtils.js" line: 377}]
startPrintWindow/<@chrome://global/content/printUtils.js:377:12
0:13.68 GECKO(3580) [Parent 3580, Main Thread] WARNING: 'nsContentUtils::GetCommonBrowserParentAncestor( remote, oldRemote) != remote', file /scratch/work/builds/mozilla-central/mozilla/dom/events/EventStateManager.cpp:1400
0:13.68 INFO Console message: [JavaScript Error: "undefined" {file: "chrome://global/content/printUtils.js" line: 377}]
startPrintWindow/<@chrome://global/content/printUtils.js:377:12
```
The eventual summary of the failure is:
```
Overall Summary
===============
mochitest-browser
~~~~~~~~~~~~~~~~~
Ran 55 checks (54 subtests, 1 tests)
Expected results: 52
Unexpected results: 3
subtest: 3 (3 fail)
Unexpected Results
------------------
toolkit/components/printing/tests/browser_modal_print.js
FAIL Test timed out -
FAIL Uncaught exception received from previously timed out test - focus listener not removed before the end of test
FAIL Found a browser window after previous test timed out -
```
This is from me running the test directly as:
```
xvfb-run ./mach test toolkit/components/printing/tests/browser_modal_print.js
```
Bug 1715653 Comment 4 Edit History
Note: The actual edited comment in the bug view page will always show the original commenter’s name and original timestamp.
Here's a snippet of the test run, with the exception that I think is causing the problem here (though I'm not entirely sure):
```
0:12.47 INFO Entering test bound testPrintMultiple
[...]
0:13.65 PASS There is one print dialog -
0:13.66 PASS The dialog is visible -
0:13.66 PASS The URL of the browser is the one we expect -
0:13.66 GECKO(3580) console.log: ***DHOLBERT _openTabModalPrint: calling getPreviewBrowser
0:13.66 GECKO(3580) console.log: ***DHOLBERT getPreviewBrowser: Entering function
0:13.66 GECKO(3580) console.log: ***DHOLBERT getPreviewBrowser: browser is non-null! returning it.
0:13.66 GECKO(3580) console.log: ***DHOLBERT _openTabModalPrint: rejecting in previewBrowser case
0:13.66 INFO Console message: [JavaScript Error: "undefined" {file: "chrome://global/content/printUtils.js" line: 377}]
startPrintWindow/<@chrome://global/content/printUtils.js:377:12
0:13.68 GECKO(3580) [Parent 3580, Main Thread] WARNING: 'nsContentUtils::GetCommonBrowserParentAncestor( remote, oldRemote) != remote', file /scratch/work/builds/mozilla-central/mozilla/dom/events/EventStateManager.cpp:1400
0:13.68 INFO Console message: [JavaScript Error: "undefined" {file: "chrome://global/content/printUtils.js" line: 377}]
startPrintWindow/<@chrome://global/content/printUtils.js:377:12
```
The eventual summary of the failure is:
```
Overall Summary
===============
mochitest-browser
~~~~~~~~~~~~~~~~~
Ran 55 checks (54 subtests, 1 tests)
Expected results: 52
Unexpected results: 3
subtest: 3 (3 fail)
Unexpected Results
------------------
toolkit/components/printing/tests/browser_modal_print.js
FAIL Test timed out -
FAIL Uncaught exception received from previously timed out test - focus listener not removed before the end of test
FAIL Found a browser window after previous test timed out -
```
This is from me running the test directly as:
```
xvfb-run ./mach test toolkit/components/printing/tests/browser_modal_print.js
```