CSS Custom Properties (Variables)

Source/core/dom/TreeScopeStyleSheetCollection.cpp

Index: Source/core/dom/TreeScopeStyleSheetCollection.cpp
diff --git a/Source/core/dom/TreeScopeStyleSheetCollection.cpp b/Source/core/dom/TreeScopeStyleSheetCollection.cpp
index 93a42764f127816bf550ff57c50f3a480f8540ba..424b51cc5accfe3d9e84af3faae8b16625548c2a 100644
--- a/Source/core/dom/TreeScopeStyleSheetCollection.cpp
+++ b/Source/core/dom/TreeScopeStyleSheetCollection.cpp
@@ -43,6 +43,7 @@ TreeScopeStyleSheetCollection::TreeScopeStyleSheetCollection(TreeScope& treeScop
     : m_treeScope(treeScope)
     , m_hadActiveLoadingStylesheet(false)
     , m_usesRemUnits(false)
+    , m_usesVariables(false)
 {
 }
 
@@ -176,18 +177,19 @@ void TreeScopeStyleSheetCollection::clearMediaQueryRuleSetStyleSheets()
     }
 }
 
-static bool styleSheetsUseRemUnits(const WillBeHeapVector<RefPtrWillBeMember<CSSStyleSheet>>& sheets)
+void TreeScopeStyleSheetCollection::updateUsesRemUnitsAndVariables()
 {
-    for (unsigned i = 0; i < sheets.size(); ++i) {
-        if (sheets[i]->contents()->usesRemUnits())
-            return true;
+    m_usesRemUnits = m_usesVariables = false;
+    unsigned numberOfStylesheets = m_activeAuthorStyleSheets.size();
+    for (unsigned i = 0; i < numberOfStylesheets; ++i) {
+        StyleSheetContents* contents = m_activeAuthorStyleSheets[i]->contents();
+        if (contents->usesRemUnits())
+            m_usesRemUnits = true;
+        if (contents->usesVariables()) {
+            ASSERT(RuntimeEnabledFeatures::cssVariablesEnabled());
+            m_usesVariables = true;
+        }
     }
-    return false;
-}
-
-void TreeScopeStyleSheetCollection::updateUsesRemUnits()
-{
-    m_usesRemUnits = styleSheetsUseRemUnits(m_activeAuthorStyleSheets);
 }
 
 DEFINE_TRACE(TreeScopeStyleSheetCollection)