CSS Custom Properties (Variables)

Source/core/dom/TreeScopeStyleSheetCollection.h

Index: Source/core/dom/TreeScopeStyleSheetCollection.h
diff --git a/Source/core/dom/TreeScopeStyleSheetCollection.h b/Source/core/dom/TreeScopeStyleSheetCollection.h
index 3ccc957b55bed47acf0d6b684debb5877204a729..e201e7f2a70a865dddde9b660502f620881b070a 100644
--- a/Source/core/dom/TreeScopeStyleSheetCollection.h
+++ b/Source/core/dom/TreeScopeStyleSheetCollection.h
@@ -53,6 +53,7 @@ public:
     bool hasStyleSheetCandidateNodes() const { return !m_styleSheetCandidateNodes.isEmpty(); }
 
     bool usesRemUnits() const { return m_usesRemUnits; }
+    bool usesVariables() const { return m_usesVariables; }
 
     void clearMediaQueryRuleSetStyleSheets();
 
@@ -83,7 +84,7 @@ protected:
     };
 
     void analyzeStyleSheetChange(StyleResolverUpdateMode, const StyleSheetCollection&, StyleSheetChange&);
-    void updateUsesRemUnits();
+    void updateUsesRemUnitsAndVariables();
 
 private:
     static StyleResolverUpdateType compareStyleSheets(const WillBeHeapVector<RefPtrWillBeMember<CSSStyleSheet>>& oldStyleSheets, const WillBeHeapVector<RefPtrWillBeMember<CSSStyleSheet>>& newStylesheets, WillBeHeapVector<RawPtrWillBeMember<StyleSheetContents>>& addedSheets);
@@ -95,6 +96,7 @@ protected:
     RawPtrWillBeMember<TreeScope> m_treeScope;
     bool m_hadActiveLoadingStylesheet;
     bool m_usesRemUnits;
+    bool m_usesVariables;
 
     DocumentOrderedList m_styleSheetCandidateNodes;
 };