[css-cascade] Define animation type of `all` as `not animatable`

[cdoublev]

Some shorthands that have non-animatable sub-properties are defined with not animatable as the value of the field Animation Type in their definition table, instead of see individual properties:

• not animatable: animation, transition, scroll-timeline
• see individual properties: all, container, view-timeline

all seems to be the only shorthand that have both animatable and non-animatable properties. I assume it is not animatable because Chrome/FF do not seem to animate it. Also, I think it would be non-trivial to filter declarations of its non-animatable properties during their expansion.

In practice, a shorthand animation type can be resolved from the animation types of its sub-properties, but it would be clearer to define it as non animatable.

[Loirooriol]

IMO shorthands should just expand into longhands, and then each longhand can animate according to its type, or not.

WebKit is able to animate all: testcase. background-color animates continuously, while width and height animate discretely between 100px and auto.

[tabatkins]

Agreed, shorthands should be treated as an expansion to their longhands and animated as much as possible.

[cdoublev]

Right, step 3 of resolving the effect value of a keyframe) should discard declarations of non-animatable properties.

Thanks for your answers.