The removal of CSSMappedAttributeDeclaration on bug 77820 caused a ~10% perf hit on the DOM/Template test.
This happens because the CSS values generated from presentation attributes are no longer created in the Document's CSSValuePool.
I'm gonna sleep on this idea, but I'm thinking we could specialize StypePropertySet for attribute styles, to share some logic with inline styles.
It would have a parent element, but wouldn't invalidateStyleAttribute() when mutating. We might also be able to use setNeedsStyleRecalc(InlineStyleChange) instead of FullStyleChange..
Created attachment 125547 [details]
Kind of a patch
This bug is a show-stopper for the Chromium port. This regression is likely causing http://crbug.com/112854 and preventing Chromium from rolling a new version of WebKit.
Andreas, could you make sure the fix get landed sooner rather than later?
kling, could you land this patch ASAP? I can land on your behalf as well if you're busy for something else.
Committed r106863: <http://trac.webkit.org/changeset/106863>