Paint/presentation timestamps in performance APIs

[noamr]

こんにちは TAG-さん!

I'm requesting an early TAG design review of Paint/presentation timestamps in performance APIs.

Aligning different paint-related timestamps in all the relevant performance APIs, by having one "interoperable" timestamp
and one coarsened platform-specific "VSync" (or "pixels on screen") timestamp.

• Explainer¹: https://github.com/w3c/paint-timing/blob/main/presentation-timestamps.md
• User research:
• Security and Privacy self-review²: Update presentation-timestamps.md to include security & privacy w3c/paint-timing#107
• GitHub repo: https://github.com/w3c/paint-timing/
• Primary contacts:
  • @noamr, Google Inc, editor
  • @mmocny, Google Inc, editor
• Organization/project driving the design: Google
• Multi-stakeholder feedback³:
  • Chromium comments: Supportive (driving)
  • Mozilla comments: hhttps://github.com/Consolidate paintTime and presentationTime in performance APIs mozilla/standards-positions#1110
  • WebKit comments: https://github.com/WebKit/standards-positions/issues/NNN
  • {{...include feedback/review from developers, implementers, civil society, and others}}

Further details:

• I have reviewed the TAG's Web Platform Design Principles
• The group where the incubation/design work on this is being done (or is intended to be done in the future):
• The group where standardization of this work is intended to be done ("unknown" if not known):
• Existing major pieces of multi-implementer review or discussion of this design:
• Major unresolved issues with or opposition to this design:
• This work is being funded by:

You should also know that...

This has been discussed in the WebPerfWG in detail over the last 2 years.

[matatk]

Hi @noamr, thanks for this review request also. We have been discussing paint/presentation timestamps today too, and have a couple of question about the explainer. We would really like to see the (end-)user needs made explicit. We'd also like to know about the alternatives that were considered, and why they found to be unsuitable, again this helps us weigh up the trade-offs. Thank you in advance for any further info you can provide.

Just in case it eases future reference: we put some background info on explainers in the other thread