Ya ya yawm TAG!

I'm requesting a TAG review of User Timing.

This is actually a request to confirm or amend previous review, as requested in the CR transition https://github.com/w3c/transitions/issues/338#issuecomment-850636248

This specification was originally developed in levels, Level 2 is a W3C Recommendation. Level 3 as WD introduced Ability to execute marks and measures across arbitrary timestamps and Support for reporting arbitrary metadata along with marks and measures. The WG wishes to drop levels, merge with the existing recommendation and use the process2020 living standard model.

• Explainer¹ (minimally containing user needs and example code): giving the history of this spec, its scope is hopefully well-understood at this point. From the Director's comment in the CR transition request, it seems that only recent additions would eventually need a review.
• Specification URL: https://w3c.github.io/user-timing/
• Tests: [wpt folder(s), if available] https://wpt.fyi/results/user-timing
• Security and Privacy self-review²: https://w3c.github.io/perf-security-privacy/#privacy-and-security-considerations
• GitHub repo (if you prefer feedback filed there): https://github.com/w3c/user-timing/issues
• Primary contacts (and their relationship to the specification): @yoavweiss, @caribouW3
• Organization(s)/project(s) driving the specification: WebPerf WG

We'd prefer the TAG provide feedback as (please delete all but the desired option):

🐛 open issues in our GitHub repo for each point of feedback

💬 leave review feedback as a comment in this issue and @-notify [github usernames]

Thank you!