Bug 163452 – 100% CPU on homedepot.com page

• Status: RESOLVED
• Resolution: FIXED
• Component: Animations

[Antti Koivisto]

The site has a keyframe animation on body. Currently this causes animation that invalidates the style of the entire document. Animations should only invalidate the element itself instead of the full subtree.

[Antti Koivisto]

<rdar://problem/28730708>

[Antti Koivisto]

Created attachment 291644 [details]
patch

[Simon Fraser (smfr)]

Comment on attachment 291644 [details]
patch

View in context: https://bugs.webkit.org/attachment.cgi?id=291644&action=review

> Source/WebCore/ChangeLog:14
> +        that causes full subtree invalidation. However animation only ever affect individual elements and
> +        the normal style resolution mechanism should be able to deal with things like inheritance as needed.

Is this true if an animation affects a property, and the element's descendants have 'inherit' for that property?

[Antti Koivisto]

> Is this true if an animation affects a property, and the element's
> descendants have 'inherit' for that property?

Yes, of course. We cache the information about use of explicit 'inherit'. Search for hasExplicitlyInheritedProperties too see the mechanism.

[Simon Fraser (smfr)]

Comment on attachment 291644 [details]
patch

View in context: https://bugs.webkit.org/attachment.cgi?id=291644&action=review

> LayoutTests/fast/animation/animation-style-update-size.html:7
> +    -webkit-animation: testframes infinite 1s;

No prefix necessary.

> LayoutTests/fast/animation/animation-style-update-size.html:10
> +@-webkit-keyframes testframes {

No prefix necessary.

> LayoutTests/fast/animation/animation-style-update-size.html:20
> +document.querySelector("body").addEventListener("animationiteration", () => {

document.body

[Antti Koivisto]

https://trac.webkit.org/changeset/207372