1392844 - Ensure that Stylo respects privacy.resistFingerprinting

Status: RESOLVED FIXED

(Core :: Layout, enhancement, P3)

Description

[Arthur Edelstein [:arthur]]

In bug 418986 , we introduced CSS patches behind the "privacy.resistFingerprinting" pref. These patches hide various fingerprintable characteristics of the system or the user's hardware that CSS normally exposes.

Mochitests are here:
https://dxr.mozilla.org/mozilla-central/source/layout/style/test/chrome/bug418986-2.js

We would like to apply these mochitests to Stylo, and patch Stylo so that they all pass.

Comment 1

[Tom Ritter [:tjr]]

There are other preferences that may be relevant. One that came up earlier was mathml.disabled.  There's also a pref that disables SVG for content; disabling graphite; stuff related to WebGL; and others - I'm not sure exactly where the line is drawn between what is and isn't in stylo.

Comment 2

[Emilio Cobos Álvarez [:emilio]]

We reuse the Gecko mechanism for media-query evaluation, so those should be respected automatically.

I think the other bit I can think of is the visited style pref, which we also respect.

Is there anything else I haven't thought of?

Comment 3

[Tom Ritter [:tjr]]

(In reply to Emilio Cobos Álvarez [:emilio] from comment #2)
> Is there anything else I haven't thought of?

We didn't think of anything right now, aside from ensuring that the tests we put in Bug 418986 are run (but I imagine stylo passing all tests is something you're already tracking if it's not done already.)

Comment 4

[Tom Ritter [:tjr]]

Tagging Arthur for advice on how to proceed.

Comment 5

[Chris Peterson [:cpeterson]]

Is there any Stylo work that still needs to be done to support privacy.resistFingerprinting?

Comment 6

[Emilio Cobos Álvarez [:emilio]]

Not as far as I can tell. At least nothing that was tested :)