CSS Custom Properties (Variables)

Source/core/dom/StyleEngine.h

Index: Source/core/dom/StyleEngine.h
diff --git a/Source/core/dom/StyleEngine.h b/Source/core/dom/StyleEngine.h
index ffe7ae975ae10cf81d7b82192fab07cd3e2455f7..2ebb3c882f6b9934609522dfe8a96d59d649d640 100644
--- a/Source/core/dom/StyleEngine.h
+++ b/Source/core/dom/StyleEngine.h
@@ -120,6 +120,8 @@ public:
 
     bool usesRemUnits() const { return m_usesRemUnits; }
     void setUsesRemUnit(bool b) { m_usesRemUnits = b; }
+    bool usesVariables() const { return m_usesVariables; }
+    void setUsesVariables(bool b) { m_usesVariables = b; }
 
     void combineCSSFeatureFlags(const RuleFeatureSet&);
     void resetCSSFeatureFlags(const RuleFeatureSet&);
@@ -288,6 +290,7 @@ private:
     bool m_usesFirstLineRules;
     bool m_usesWindowInactiveSelector;
     bool m_usesRemUnits;
+    bool m_usesVariables;
     unsigned m_maxDirectAdjacentSelectors;
 
     bool m_ignorePendingStylesheets;