Web Animations: Introduce ActiveAnimations and AnimationStack

Source/core/css/resolver/StyleResolver.h

Index: Source/core/css/resolver/StyleResolver.h
diff --git a/Source/core/css/resolver/StyleResolver.h b/Source/core/css/resolver/StyleResolver.h
index eaafb13097782c9c3769eacbba5c16f7d9ce0367..50b99a2645339fa2ccd3c9422ab1efda8bf3042c 100644
--- a/Source/core/css/resolver/StyleResolver.h
+++ b/Source/core/css/resolver/StyleResolver.h
@@ -61,6 +61,7 @@ class CSSStyleSheet;
 class CSSValue;
 class ContainerNode;
 class Document;
+class DocumentTimeline;
 class Element;
 class ElementRuleCollector;
 class Frame;
@@ -261,7 +262,7 @@ private:
     template <StyleApplicationPass pass>
     void applyProperties(const StylePropertySet* properties, StyleRule*, bool isImportant, bool inheritedOnly, PropertyWhitelistType = PropertyWhitelistNone);
     template <StyleApplicationPass pass>
-    void applyAnimatedProperties(const Element* target);
+    void applyAnimatedProperties(const Element*, const DocumentTimeline*);
     void resolveVariables(CSSPropertyID, CSSValue*, Vector<std::pair<CSSPropertyID, String> >& knownExpressions);
     void matchPageRules(MatchResult&, RuleSet*, bool isLeftPage, bool isFirstPage, const String& pageName);
     void matchPageRulesForList(Vector<StyleRulePage*>& matchedRules, const Vector<StyleRulePage*>&, bool isLeftPage, bool isFirstPage, const String& pageName);