Skeleton implementation of CSS Properties and Values API

third_party/WebKit/Source/core/css/ComputedStyleCSSValueMapping.cpp

Index: third_party/WebKit/Source/core/css/ComputedStyleCSSValueMapping.cpp
diff --git a/third_party/WebKit/Source/core/css/ComputedStyleCSSValueMapping.cpp b/third_party/WebKit/Source/core/css/ComputedStyleCSSValueMapping.cpp
index 971b96a413a66645468e42fcbca489bdcf1caca1..c26d07a70a309c4e1f6a9afc98d6415306062957 100644
--- a/third_party/WebKit/Source/core/css/ComputedStyleCSSValueMapping.cpp
+++ b/third_party/WebKit/Source/core/css/ComputedStyleCSSValueMapping.cpp
@@ -53,6 +53,7 @@
 #include "core/css/CSSURIValue.h"
 #include "core/css/CSSValueList.h"
 #include "core/css/CSSValuePair.h"
+#include "core/css/PropertyRegistry.h"
 #include "core/layout/LayoutBlock.h"
 #include "core/layout/LayoutBox.h"
 #include "core/layout/LayoutGrid.h"
@@ -1633,9 +1634,18 @@ static EBreak mapToColumnBreakValue(EBreak genericBreakValue)
     }
 }
 
-const CSSValue* ComputedStyleCSSValueMapping::get(const AtomicString customPropertyName, const ComputedStyle& style)
+const CSSValue* ComputedStyleCSSValueMapping::get(const AtomicString customPropertyName, const ComputedStyle& style, const PropertyRegistry* registry)
 {
     StyleVariableData* variables = style.variables();
+    if (const PropertyRegistry::Registration* registration = registry->registration(customPropertyName)) {
+        if (variables) {
+            const CSSValue* result = variables->registeredInheritedProperty(customPropertyName);
+            if (result)
+                return result;
+        }
+        return registration->initial();
+    }
+
     if (!variables)
         return nullptr;