Review WebGL mitigations

We should review Firefox's existing WebGL patch and see if we have sufficient protections.

added component::applications/tor browser in Legacy / Trac ff60-esr in Legacy / Trac owner::tbb-team in Legacy / Trac priority::medium in Legacy / Trac severity::normal in Legacy / Trac status::new in Legacy / Trac type::defect in Legacy / Trac labels

mentioned in issue legacy/trac#30541 (moved)

moved from legacy/trac#26198 (moved)

added Bug label and removed 1 deleted label

removed 1 deleted label

@richard Fingerprinting label, TIA

added Fingerprinting label

added Backlog Task labels

added Icebox label and removed Backlog label

removed Icebox label

added Roadmap::Future label

removed Bug label

added All Platforms label

mentioned in issue #30537

marked this issue as related to #42239

added Apps::Type::Audit label