WIP Support var() references in registered custom property keyframes

third_party/WebKit/Source/core/animation/CSSInterpolationType.cpp

Index: third_party/WebKit/Source/core/animation/CSSInterpolationType.cpp
diff --git a/third_party/WebKit/Source/core/animation/CSSInterpolationType.cpp b/third_party/WebKit/Source/core/animation/CSSInterpolationType.cpp
index f2dc1ed9971affee08c250e87a3f822f79a8b856..e93144e39e98e170894264fb1946bff8c4a3ed47 100644
--- a/third_party/WebKit/Source/core/animation/CSSInterpolationType.cpp
+++ b/third_party/WebKit/Source/core/animation/CSSInterpolationType.cpp
@@ -220,17 +220,11 @@ CSSInterpolationType::MaybeConvertCustomPropertyDeclarationInternal(
     return MaybeConvertValue(*value, &state, conversion_checkers);
   }
 
-  if (declaration.Value()->NeedsVariableResolution()) {
-    // TODO(alancutter): Support smooth interpolation with var() values for
-    // registered custom properties. This requires integrating animated custom
-    // property value application with the CSSVariableResolver to apply them in
-    // the appropriate order defined by the chain of var() dependencies.
-    // All CSSInterpolationTypes should fail convertion here except for
-    // CSSValueInterpolationType.
-    return nullptr;
-  }
-
   if (registration_) {
+    if (declaration.Value()->NeedsVariableResolution()) {
+      return nullptr;
+    }
+
     const CSSValue* parsed_value =
         declaration.Value()->ParseForSyntax(registration_->Syntax());
     if (parsed_value) {