I confirmed that we're actually using this codepath by manually testing
<input type=color>: it works with the patch, but if I comment out the
call to nsHTMLCSSStyleSheet::PseudoElementRulesMatching from
nsStyleSet::RuleNodeWithReplacement, then the color swatch breaks, which
proves that we're depending on the code.
I think I included this in the queue because it is needed for patch 22,
although I've forgotten the full reasoning.
Note that this means that when we start transitions, we post restyles
that are processed during the current restyling operation, rather than
in a later phase. This depends on patch 11, which makes the transition
manager skip style changes that it posts while starting transitions, to
ensure that this doesn't lead to an infinite loop. This also depends on
patch 16, which only consumes restyle data for the primary frame, to
ensure that the animation restyles posted are processed properly. It
also depends on patch 14, which makes us retain data on finished
transitions, to avoid triggering extra transitions on descendants when
both an ancestor and a descendant transition an inherited property, and
the descendant does so faster.
This fixes a known failure in layout/style/test/test_animations.html and
test_animations_omta.html (as visible in the patch). I believe this is
because this patch changes us to compute keyframe values for animations
on top of a style context *with* animation data rather than one without,
which means what we're computing them on top of changes each time. (The
purpose of patch 3 was to avoid this in the case where avoiding it
matters, i.e., implicit 0% and 100% keyframes.)
This is needed for patch 17, which removes restyling phases, so that
when the transition manager posts a restyle to undo the covering done by
the cover rule, that restyle doesn't get consumed by an inner frame.
Note that this increases memory use for completed transitions since we
don't throw away the data when the transitions complete. That said,
this matches what we do for CSS Animations, and it's needed (once we
switch to the new rules for starting transitions) to maintain the
invariant that unrelated style changes don't trigger transitions.
The storage issues could be optimized in the future if it turns out to
be a problem, but I think that's unlikely, given that we'll never store
more than one for any element+property combination.
This is needed to prevent these reftests from failing:
layout/reftests/svg/smil/smil-transitions-interaction-1a.svg
layout/reftests/svg/smil/smil-transitions-interaction-1b.svg
layout/reftests/svg/smil/smil-transitions-interaction-2a.svg
layout/reftests/svg/smil/smil-transitions-interaction-2b.svg
layout/reftests/svg/smil/smil-transitions-interaction-4a.svg
layout/reftests/svg/smil/smil-transitions-interaction-4b.svg
The mIsCSS path fixes the a tests, and the !mIsCSS path fixes the b tests.
This is because this patch series changes the way in which transitions
interact with other types of animations to depend on those animations
being flushed in the animation-only style flush. (The relevant call is
added in patch 6, though we don't really depend on it until patch 17.)
This depends on bug 1087536 patch 3, which posts animation restyles
using the eRestyle_CSSTransitions and eRestyle_CSSAnimations hints.
This is used by patch 6.
This is needed to make the tests for bug 686656 in test_animations.html
pass.
Note that once the rest of bug 960465 happens this will start producing
slightly different results in edge cases, since we will only be skipping
animation styles for the element itself and not for ancestors. However,
both old and new behaviors are incorrect, since per spec we should be
updating the base values dynamically (bug 1064915).
