[tbb-dev] How to enable window.performance.timing on TBB

[Matthew Finkel]

On 2019-11-06 23:12, Zhao Zhang wrote:
> Hi there,

Hi!

> 
> Sorry I have a silly question, currently I'm preparing some timing
> analysis on TorBrowser and find that it looks like most of
> window.performance info has been disabled (I think, for security
> reasons).
> It returns all 0s for executing script "window.performance.timing",
> and returns empty [] for executing window.performance.getEntries(). 
> 
> I've looked through about:config, tried modifying 
> 
> devtools.dom.enabled;true 
> dom.enable_performance;true
> 
> but looks still no effect. So where is the proper way to enable
> performance timing? Thanks.

Indeed. This API is disabled by the privacy.resistFingerprinting pref.
We began experimenting with a way of working around this, but we haven't
succeeded yet (mostly due to lack of time).

https://trac.torproject.org/projects/tor/ticket/30932

Sorry we don't have a more helpful answer right now.

- Matt