Chrome 146 scroll-triggered animations

[chrisdavidmills]

Summary

Chrome 146 adds support for scroll-triggered animations; see https://chromestatus.com/feature/5181996801982464.

The latest Chrome collector PR has added BCD for several of the related features; my PR adds a few more, namely the <animation-action> data type, and the related range properties, which are supported but currently under an old name.

Test results and supporting details

Related issues

[github-actions]

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[caugner]

We discussed support data for CSS types in the BCD meeting on 2026-01-20 and the consensus was to record support data under the individual CSS properties instead of for the CSS type itself. The guidelines are yet to be written though: #28913

CSS types are a bit like mixins, so even though all the properties here likely support the same values for <animation-action>, it is better to actually test using the collector. I'll add the "needs collector test" label.

[chrisdavidmills]

OK, I'll wait for #29033 to be merged before doing anything about this.

I agree that CSS types are a bit like API mixins, but unlike mixins, we document CSS types on their own separate pages.

[chrisdavidmills]

Setting this to draft status for now, as the range properties have the wrong names. They were recently renamed in a CSS WG resolution (see w3c/csswg-drafts#13174 and w3c/csswg-drafts#13307), which hasn't made it to the spec yet. Chromium supports them using the latest correct names, so there is no need for alternative names here.

I'll correct these when the spec has been updated.