Workers not farbling user agent properly - follow up to 12097

[LaurenWags]

Description

When Fingerprinting = strict, the "Worker" column value should match the other values in the row for User Agent on the QA pages. This is not occurring.

Steps to Reproduce

1. Clean profile 1.17.x
2. Visit https://dev-pages.brave.software/farbling.html and https://dev-pages.bravesoftware.com/farbling.html
3. With FP = standard (default), click Generate fingerprints on both pages.
4. See FP values are the same across the User Agent row (expected, since "Mode" column says strict.
5. Change FP = strict for both pages.
6. Click Generate fingerprints on both pages.

Actual result:

Worker column value for the User Agent row is different than other values in that row. It is the same value from when FP = standard and it is the same between both pages:

Expected result:

all values in User Agent row should be the same when FP = strict

Reproduces how often:

easily

Brave version (brave://version info)

Brave	1.17.55 Chromium: 86.0.4240.111 (Official Build) dev (x86_64)
Revision	b8c36128a06ebad76af51591bfec980224db5522-refs/branch-heads/4240@{#1290}
OS	macOS Version 10.14.6 (Build 18G6032)

Brave	1.18.17 Chromium: 87.0.4280.27 (Official Build) nightly (x86_64)
Revision	d8c1fe98de8d9c6bd46ebe8b0cc9d2b6bdccca1e-refs/branch-heads/4280@{#556}
OS	macOS Version 10.14.6 (Build 18G6032)

Version/Channel Information:

• Can you reproduce this issue with the current release? n/a for 1.16.x, this should be fully implemented with 1.17.x per Fingerprinting 2.0: User Agent #9190 (comment)
• Can you reproduce this issue with the beta channel? yes 1.17.x
• Can you reproduce this issue with the nightly channel? yes 1.18.x

Other Additional Information:

• Does the issue resolve itself when disabling Brave Shields? n/a
• Does the issue resolve itself when disabling Brave Rewards? n/a
• Is the issue reproducible on the latest version of Chrome? n/a

Miscellaneous Information:

cc @pes10k @pilgrim-brave

[pes10k]

thanks @LaurenWags ! Was just wondering, do you see the issue in nightly? Im not able to reproduce there at least, so hopefully this just means something needs to be uplifted or retagged 🤞

[pes10k]

Specifically it looks like it might be solved by brave/brave-core#6906

[LaurenWags]

@pes10k yes I can reproduce on nightly 1.18.17 with a clean profile:

Brave | 1.18.17 Chromium: 87.0.4280.27 (Official Build) nightly (x86_64)
-- | --
Revision | d8c1fe98de8d9c6bd46ebe8b0cc9d2b6bdccca1e-refs/branch-heads/4280@{#556}
OS | macOS Version 10.14.6 (Build 18G6032)

[LaurenWags]

ah, ok that one didn't make it into 1.18.17. let me try 1.18.18.

[LaurenWags]

Does not reproduce with 1.18.18

Brave	1.18.18 Chromium: 87.0.4280.27 (Official Build) nightly (x86_64)
Revision	d8c1fe98de8d9c6bd46ebe8b0cc9d2b6bdccca1e-refs/branch-heads/4280@{#556}
OS	macOS Version 10.14.6 (Build 18G6032)

[bsclifton]

Closing as this should be fixed in later versions - cc: @pes10k in case I have that wrong

[pes10k]

@bsclifton this is not ready to be closed yet, its waiting on a fix @pilgrim-brave is working on to land (see brave/brave-core#7596)

[stephendonner]

Verified FIXED using the inline testcase, with

Brave	1.21.50 Chromium: 88.0.4324.152 (Official Build) beta (x86_64)
Revision	6579930fc53b4dc589c042bec9d0a3778326974d-refs/branch-heads/4324@{#2106}
OS	macOS Version 11.2.1 (Build 20D74)

---

Verification passed on

Brave	1.21.56 Chromium: 88.0.4324.152 (Official Build) dev (64-bit)
Revision	6579930fc53b4dc589c042bec9d0a3778326974d-refs/branch-heads/4324@{#2106}
OS	Ubuntu 18.04 LTS

Verified test plan from the description

---

Verification passed on

Brave | 1.21.63 Chromium: 88.0.4324.182 (Official Build) dev (64-bit)
-- | --
Revision | 73ee5087001dcef33047c4ed650471b225dd8caf-refs/branch-heads/4324@{#2202}
OS | Windows 10 OS Version 2004 (Build 19041.804)

Verified test plan from the description

When FB is default (standard) values are the same across the User Agent row

https://dev-pages.brave.software/farbling.html	https://dev-pages.bravesoftware.com/farbling.html

When FB is strict values are the same across the User Agent row

https://dev-pages.brave.software/farbling.html	https://dev-pages.bravesoftware.com/farbling.html

[srirambv]

Verification passed on OnePlus 6T with Android 10 running 1.21.70 x64 build

• Verified worker column has the same values as others for UA

FP=Standard

FP=Strict

---

Verification passed on Samsung Tab A with Android 10 running 1.21.70 x64 build

• Verified worker column has the same values as others for UA

FP=Standard

FP=Strict