WIP Support var() references in registered custom property keyframes

third_party/WebKit/Source/core/css/resolver/StyleResolverState.h

Index: third_party/WebKit/Source/core/css/resolver/StyleResolverState.h
diff --git a/third_party/WebKit/Source/core/css/resolver/StyleResolverState.h b/third_party/WebKit/Source/core/css/resolver/StyleResolverState.h
index 02a72da35e9bedfc2bec8add924b9582d0714b56..10e6521fb768d6daea9c4e72fe07353aa4c45741 100644
--- a/third_party/WebKit/Source/core/css/resolver/StyleResolverState.h
+++ b/third_party/WebKit/Source/core/css/resolver/StyleResolverState.h
@@ -103,6 +103,9 @@ class CORE_EXPORT StyleResolverState {
   }
 
   CSSAnimationUpdate& AnimationUpdate() { return animation_update_; }
+  const CSSAnimationUpdate& AnimationUpdate() const {
+    return animation_update_;
+  }
 
   bool IsAnimationInterpolationMapReady() const {
     return is_animation_interpolation_map_ready_;
@@ -118,6 +121,10 @@ class CORE_EXPORT StyleResolverState {
     is_animating_custom_properties_ = value;
   }
 
+  HashSet<PropertyHandle>& CustomPropertiesPendingAnimationApplication() {
+    return custom_properties_pending_animation_application_;
+  }
+
   void SetParentStyle(PassRefPtr<ComputedStyle> parent_style) {
     parent_style_ = std::move(parent_style);
   }
@@ -237,6 +244,7 @@ class CORE_EXPORT StyleResolverState {
   CSSAnimationUpdate animation_update_;
   bool is_animation_interpolation_map_ready_;
   bool is_animating_custom_properties_;
+  HashSet<PropertyHandle> custom_properties_pending_animation_application_;
 
   bool apply_property_to_regular_style_;
   bool apply_property_to_visited_link_style_;