If the element has throttled animations that will be affected by pending style
changes, the throttled animations will be updated though sequential tasks after
normal styling process. E.g. UpdateEffectProperties, UpdateCascadeResults etc.
So we don't need to flush them in advance of the sequential tasks.
The first test case in this patch fails without this fix.
MozReview-Commit-ID: GystAqK2bQE
(Path is actually r=froydnj.)
Bug 1400459 devirtualized nsIAtom so that it is no longer a subclass of
nsISupports. This means that nsAtom is now a better name for it than nsIAtom.
MozReview-Commit-ID: 91U22X2NydP
Implement GetTarget() and functions of CSSPseudoElement.
We use a strong reference from CSSPseudoElement to Element and a non-owning
reference from Element to CSSPseudoElement.