Only use a subset of user-installed fonts to farble

[arthuredelstein]

We are going to constrain font farbling to only those that are present on the fingerprint.js script.

[stephendonner]

Hi @arthuredelstein ! Mind adding a testplan here, when you get a chance? Thanks! Adding QA/Blocked and QA/Test-Plan-Required just until we've got that, and then we'll be fully unblocked 👍

[arthuredelstein]

QA test plan: Please confirm that this test still behaves as expected: https://dev-pages.brave.software/fingerprinting/fonts.html
Also it may be useful to repeat the test with a difference preferred language.

[stephendonner]

Verification PASSED using

Brave | 1.62.73 Chromium: 119.0.6045.163 (Official Build) nightly (x86_64)
-- | --
Revision | 522e9147d931744b1641084046c197caf7b341f0
OS | macOS Version 11.7.10 (Build 20G1427)

Steps:

1. installed 1.62.73
2. launched Brave
3. loaded https://dev-pages.brave.software/fingerprinting/fonts.html
4. followed the instructions from the above page (I already have fredoka one installed from past tests; the font is no longer available at the link provided)
5. clicked Start tests
6. confirmed the Control and Test widths of the sample string mmmmmmmmmmlli are the same
7. clicked on the Other site link at https://dev-pages.brave.software/fingerprinting/fonts.html

Confirmed both sets of test pages pass

example	example	example

Also installed and configured Spanish - United States:

example	example	example	example

[MadhaviSeelam]

Verification Passed using

Brave | 1.62.100 Chromium: 120.0.6099.71 (Official Build) beta (64-bit)
-- | --
Revision | ac084eaa0f81aa9ef631c2ca81a02469a4ee1a4a
OS | Windows 11 Version 22H2 (Build 22621.2715)

Steps:

1. installed 1.62.100
2. launched Brave
3. loaded https://dev-pages.brave.software/fingerprinting/fonts.html
4. followed the instructions from the above page (installed fredoka one via github; the font is no longer available at the link provided)
5. clicked Start tests
6. confirmed the Control and Test widths of the sample string mmmmmmmmmmlli are the same
7. clicked on the Other site link at https://dev-pages.brave.software/fingerprinting/fonts.html

Confirmed both sets of test pages pass

example	example	example

Also installed and configured France:

example	example	example	example

[hffvld]

Verified on Pixel 7 using version(s):

Device/OS: Pixel 7 / panther_beta-user 14 AP11.231020.013.A1 release-keys
Brave build: 1.62.130
Chromium: 120.0.6099.199 (Official Build) beta (64-bit) 

Filed follow-up issue #35188

STEPS:

1. Use Samsung device
2. Launch Chrome > Go to https://arthuredelstein.net/demos/font.html
3. Confirm that Attempting to load Samsung Color Emoji uses Samsung emoji design
4. Launch Brave > Go to https://arthuredelstein.net/demos/font.html
5. Disable Brave Shields > Confirm that Attempting to load Samsung Color Emoji uses Samsung emoji design
6. Now enable Brave shields > Refresh the page > Observe, that Brave still uses Samsung emoji design instead of Google Noto Emoji design

ACTUAL RESULTS:

• Observed that font restrictions are not getting applied on Android devices.

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Chrome	Brave. Shields OFF	Brave. Shields ON