Wrong fonts on https://brendaneich.github.io/sieve/

[pilgrim-brave]

Text should be monospaced but is displayed in a proportional font. As per discussion in Slack, this is likely caused by font whitelisting. CSS uses font-family: "Courier" and relies on font engine to substitute a modern monospaced font like Courier New.

[pilgrim-brave]

Affects Mac and Windows only. Linux desktop build currently has no font whitelist, and Android already has "Courier" on the whitelist for unrelated reasons.

[LaurenWags]

@pes10k @pilgrim-brave since this has QA/Yes, a test plan is needed.

Marking as QA/Blocked until there is one.

cc @kjozwiak @rebron

[pes10k]

@pilgrim-brave do we have a browser test for this? If so, i think we can QA/No it, wdyt?

[pilgrim-brave]

We do not have automated testing for this. Visit the link in the title, right-click any number in the grid and select Inspect, go to Computed tab in devtools, scroll down to Rendered Fonts section to see what font it's actually using for rendering. Correct answer on Mac is "Courier", as per this screenshot:

[stephendonner]

Verified PASSED using

Brave	1.47.110 Chromium: 108.0.5359.71 (Official Build) beta (x86_64)
Revision	1e0e3868ee06e91ad636a874420e3ca3ae3756ac-refs/branch-heads/5359@{#1016}
OS	macOS Version 13.1 (Build 22C5059b)

Steps:

1. installed 1.47.110
2. launched Brave
3. loaded https://brendaneich.github.io/sieve/
4. opened Developer Tools and inspected an element
5. looked at its font-family

Confirmed the font-family used is Courier

[MadhaviSeelam]

Verification PASSED

Brave | 1.47.125 Chromium: 108.0.5359.99 (Official Build) beta (64-bit)
-- | --
Revision | 410951fc34bb4b2cbf182231f9f779efaafaf682-refs/branch-heads/5359_71@{#9}
OS | Windows 11 Version 21H2 (Build 22000.1219)

Steps:

1. installed 1.47.110
2. launched Brave
3. loaded https://brendaneich.github.io/sieve/
4. opened Developer Tools and inspected an element
5. looked at its font-family

Confirmed the font-family used is Courier