Followup #10605: Fixes window isFocused function that was not updated

[NejcZdovc]

Submitter Checklist:

• Submitted a ticket for my issue if one did not already exist.
• Used Github auto-closing keywords in the commit message.
• Added/updated tests for this change (for new code or code which already has tests).
• Ran git rebase -i to squash commits (if needed).
• Tagged reviewers and labelled the pull request as needed.

This happened because #10458 was stale for long then #10605 was stale again and not rebase to the latest master before merging.

Auditors: @bbondy

Test Plan:

• try to run brave
• brave should start normally

Reviewer Checklist:

Tests

• Adequate test coverage exists to prevent regressions
• Tests should be independent and work correctly when run individually or as a suite ref
• New files have MPL2 license header

[codecov-io]

Codecov Report

Merging #10991 into master will not change coverage.
The diff coverage is 0%.

@@           Coverage Diff           @@
##           master   #10991   +/-   ##
=======================================
  Coverage   54.21%   54.21%           
=======================================
  Files         249      249           
  Lines       21816    21816           
  Branches     3395     3395           
=======================================
  Hits        11827    11827           
  Misses       9989     9989

Flag	Coverage Δ
#unittest	54.21% <0%> (ø)	⬆️

Impacted Files	Coverage Δ
app/renderer/components/navigation/navigator.js	75.18% <0%> (ø)	⬆️

[cezaraugusto]

merging now as mentioned PR made master unusable ++