Prepare for responsive CSS animations.

Source/core/animation/css/CSSAnimationUpdate.h

Index: Source/core/animation/css/CSSAnimationUpdate.h
diff --git a/Source/core/animation/css/CSSAnimationUpdate.h b/Source/core/animation/css/CSSAnimationUpdate.h
index af58fce4211dd1a01214f398e778f6dc2f3873f6..a67499bc7dd72b8aad2b2b9c0da15f8b17d2d7db 100644
--- a/Source/core/animation/css/CSSAnimationUpdate.h
+++ b/Source/core/animation/css/CSSAnimationUpdate.h
@@ -15,6 +15,7 @@ namespace blink {
 
 class AnimationPlayer;
 class InertAnimation;
+class KeyframeEffectModelBase;
 
 // This class stores the CSS Animations/Transitions information we use during a style recalc.
 // This includes updates to animations/transitions as well as the Interpolations to be applied.
@@ -83,6 +84,37 @@ public:
         unsigned styleRuleVersion;
     };
 
+    class UpdatedAnimationStyle {
+        ALLOW_ONLY_INLINE_ALLOCATION();
+    public:
+        struct CompositableStyleSnapshot {
+            RefPtrWillBeMember<AnimatableValue> opacity;
+            RefPtrWillBeMember<AnimatableValue> transform;
+            RefPtrWillBeMember<AnimatableValue> webkitFilter;
+        };
+
+        UpdatedAnimationStyle()
+        {
+        }
+
+        UpdatedAnimationStyle(AnimationPlayer* player, KeyframeEffectModelBase* effect, const UpdatedAnimationStyle::CompositableStyleSnapshot& snapshot)
+            : player(player)
+            , effect(effect)
+            , snapshot(snapshot)
+        {
+        }
+
+        void trace(Visitor* visitor)
+        {
+            visitor->trace(player);
+            visitor->trace(effect);
+        }
+
+        RawPtrWillBeMember<AnimationPlayer> player;
+        RawPtrWillBeMember<KeyframeEffectModelBase> effect;
+        CompositableStyleSnapshot snapshot;
+    };
+
     void startAnimation(const AtomicString& animationName, PassRefPtrWillBeRawPtr<InertAnimation> animation, const Timing& timing, PassRefPtrWillBeRawPtr<StyleRuleKeyframes> styleRule)
     {
         animation->setName(animationName);
@@ -105,6 +137,10 @@ public:
         m_animationsWithUpdates.append(UpdatedAnimation(name, player, animation, specifiedTiming, styleRule));
         m_suppressedAnimationPlayers.add(player);
     }
+    void updateAnimationStyle(AnimationPlayer* player, KeyframeEffectModelBase* effect, const UpdatedAnimationStyle::CompositableStyleSnapshot& snapshot)
+    {
+        m_animationsWithStyleUpdates.append(UpdatedAnimationStyle(player, effect, snapshot));
+    }
 
     void startTransition(CSSPropertyID id, CSSPropertyID eventId, const AnimatableValue* from, const AnimatableValue* to, PassRefPtrWillBeRawPtr<InertAnimation> animation)
     {
@@ -125,6 +161,7 @@ public:
     const WillBeHeapHashSet<RawPtrWillBeMember<const AnimationPlayer>>& suppressedAnimationAnimationPlayers() const { return m_suppressedAnimationPlayers; }
     const Vector<AtomicString>& animationsWithPauseToggled() const { return m_animationsWithPauseToggled; }
     const WillBeHeapVector<UpdatedAnimation>& animationsWithUpdates() const { return m_animationsWithUpdates; }
+    const WillBeHeapVector<UpdatedAnimationStyle>& animationsWithStyleUpdates() const { return m_animationsWithStyleUpdates; }
 
     struct NewTransition {
         ALLOW_ONLY_INLINE_ALLOCATION();
@@ -159,6 +196,7 @@ public:
             && m_suppressedAnimationPlayers.isEmpty()
             && m_animationsWithPauseToggled.isEmpty()
             && m_animationsWithUpdates.isEmpty()
+            && m_animationsWithStyleUpdates.isEmpty()
             && m_newTransitions.isEmpty()
             && m_cancelledTransitions.isEmpty()
             && m_activeInterpolationsForAnimations.isEmpty()
@@ -177,6 +215,7 @@ private:
     WillBeHeapHashSet<RawPtrWillBeMember<const AnimationPlayer>> m_suppressedAnimationPlayers;
     Vector<AtomicString> m_animationsWithPauseToggled;
     WillBeHeapVector<UpdatedAnimation> m_animationsWithUpdates;
+    WillBeHeapVector<UpdatedAnimationStyle> m_animationsWithStyleUpdates;
 
     NewTransitionMap m_newTransitions;
     HashSet<CSSPropertyID> m_cancelledTransitions;