WIP Support var() references in registered custom property keyframes

third_party/WebKit/Source/core/animation/css/CSSAnimations.h

Index: third_party/WebKit/Source/core/animation/css/CSSAnimations.h
diff --git a/third_party/WebKit/Source/core/animation/css/CSSAnimations.h b/third_party/WebKit/Source/core/animation/css/CSSAnimations.h
index 1c654c78b17c03ed2a9b2a0f8a14485ee65e3523..d98005b1cf6968762234971ce4575f8d5586e2da 100644
--- a/third_party/WebKit/Source/core/animation/css/CSSAnimations.h
+++ b/third_party/WebKit/Source/core/animation/css/CSSAnimations.h
@@ -64,7 +64,6 @@ class CSSAnimations final {
   static bool IsAnimationAffectingProperty(CSSPropertyID);
   static bool IsAffectedByKeyframesFromScope(const Element&, const TreeScope&);
   static bool IsAnimatingCustomProperties(const ElementAnimations*);
-  static bool IsCustomPropertyHandle(const PropertyHandle&);
   static void CalculateAnimationUpdate(CSSAnimationUpdate&,
                                        const Element* animating_element,
                                        Element&,
@@ -157,7 +156,9 @@ class CSSAnimations final {
 
   CSSAnimationUpdate pending_update_;
 
-  ActiveInterpolationsMap previous_active_interpolations_for_animations_;
+  ActiveInterpolationsMap previous_active_interpolations_for_custom_animations_;
+  ActiveInterpolationsMap
+      previous_active_interpolations_for_standard_animations_;
 
   struct TransitionUpdateState {
     STACK_ALLOCATED();