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 c1eea4842862e0bc8e8526944aa8f6114e3b10f5..a9413ecc0a8c09625ec02b0797e39ab30d0fefea 100644
--- a/third_party/WebKit/Source/core/css/resolver/StyleResolverState.h
+++ b/third_party/WebKit/Source/core/css/resolver/StyleResolverState.h
@@ -102,6 +102,9 @@ 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_;
@@ -117,6 +120,14 @@ class CORE_EXPORT StyleResolverState {
     is_animating_custom_properties_ = value;
   }
 
+  HashSet<PropertyHandle>& AnimationPendingCustomProperties() {
+    return animation_pending_custom_properties_;
+  }
+
+  const HashSet<PropertyHandle>& AnimationPendingCustomProperties() const {
+    return animation_pending_custom_properties_;
+  }
+
   void SetParentStyle(PassRefPtr<ComputedStyle> parent_style) {
     parent_style_ = std::move(parent_style);
   }
@@ -236,6 +247,7 @@ class CORE_EXPORT StyleResolverState {
   CSSAnimationUpdate animation_update_;
   bool is_animation_interpolation_map_ready_;
   bool is_animating_custom_properties_;
+  HashSet<PropertyHandle> animation_pending_custom_properties_;
 
   bool apply_property_to_regular_style_;
   bool apply_property_to_visited_link_style_;