1510991 - Add catch-all use-counters for unimplemented platform features

Status: NEW

(Core :: General, enhancement, P3)

Description

[Dietrich Ayala (:dietrich)]

We want visibility into features used in web content that are not implemented in Firefox.

An example where this can be useful is the css webkit alias work in bug 1170789.

Given that compat / interop is going to be a focus in 2019, let's get support for this set up, so that we're ready to add feature coverage as needed.

Comment 1

[Georg Fritzsche [:gfritzsche]]

Dietrich, is there maybe a better bugzilla component for this bug that is more platform specific?
If not we can temporarily track it here.

Comment 2

[Dietrich Ayala (:dietrich)]

Will apply to CSS, DOM and JS so I put it in Core::General.

Comment 3

[Dietrich Ayala (:dietrich)]

List of web platform features implemented by Chromium that we do not support (with some noise - not 100% correct), shared by Tim Smith.

https://docs.google.com/spreadsheets/d/1A1A87DSg-XGq6QTkZ3okVrC2er5e3YrF1xqHdcN-eCw/edit#gid=676202541

Comment 4

[Tim Smith (inactive) 👨‍🔬 [:tdsmith]]

FWIW my presumption is that the list is correct but not necessarily meaningful -- e.g. we expose Window#applicationCache but not the corresponding initial-capped Window#ApplicationCache interface object, which is required by the controlling WebIDL but may not be useful, so its absence may not represent any interop risk.

The list was processed from the Chrome Web API confluence data from https://github.com/GoogleChromeLabs/confluence; it's intended to represent APIs that are present in latest Chrome and which Firefox has never shipped.