CSS Custom Properties (Variables)

Source/core/css/resolver/CSSPropertyPriority.h

Index: Source/core/css/resolver/CSSPropertyPriority.h
diff --git a/Source/core/css/resolver/CSSPropertyPriority.h b/Source/core/css/resolver/CSSPropertyPriority.h
index 3edca213d50cd3e52a5cf24fa10f37dfbe22fccb..0a1e793afd186b714808fb59f923d075ade6395e 100644
--- a/Source/core/css/resolver/CSSPropertyPriority.h
+++ b/Source/core/css/resolver/CSSPropertyPriority.h
@@ -14,6 +14,7 @@ namespace blink {
 // decides the pixel value of low priority properties with 'em' units.
 
 enum CSSPropertyPriority {
+    ResolveVariables,
     HighPropertyPriority,
     LowPropertyPriority
 };
@@ -30,6 +31,19 @@ public:
 };
 
 template<>
+inline CSSPropertyID CSSPropertyPriorityData<ResolveVariables>::first()
+{
+    static_assert(CSSPropertyVariable == lastCSSProperty, "CSSPropertyVariable should be the last property.");
+    return CSSPropertyVariable;
+}
+
+template<>
+inline CSSPropertyID CSSPropertyPriorityData<ResolveVariables>::last()
+{
+    return CSSPropertyVariable;
+}
+
+template<>
 inline CSSPropertyID CSSPropertyPriorityData<HighPropertyPriority>::first()
 {
     static_assert(CSSPropertyColor == firstCSSProperty, "CSSPropertyColor should be the first high priority property");
@@ -54,7 +68,8 @@ inline CSSPropertyID CSSPropertyPriorityData<LowPropertyPriority>::first()
 template<>
 inline CSSPropertyID CSSPropertyPriorityData<LowPropertyPriority>::last()
 {
-    return static_cast<CSSPropertyID>(lastCSSProperty);
+    static_assert(lastCSSProperty - 1 < CSSPropertyVariable, "CSSPropertyVariable shouldn't be included in low priority properties.");
+    return static_cast<CSSPropertyID>(lastCSSProperty - 1);
 }
 
 } // namespace blink