Add forEach() to CSSVariablesMap

Source/core/css/CSSVariablesMap.h

Index: Source/core/css/CSSVariablesMap.h
diff --git a/Source/core/css/CSSVariablesMap.h b/Source/core/css/CSSVariablesMap.h
index bd7878a41591876275d5d1718052422c7e838577..fea2f42638971eb96bf70c06e6a07054495a3cfc 100644
--- a/Source/core/css/CSSVariablesMap.h
+++ b/Source/core/css/CSSVariablesMap.h
@@ -29,6 +29,7 @@
 #define CSSVariablesMap_h
 
 #include "RuntimeEnabledFeatures.h"
+#include "core/css/CSSVariablesMapForEachCallback.h"
 #include "wtf/RefCounted.h"
 #include "wtf/text/WTFString.h"
 
@@ -53,6 +54,9 @@ public:
     void set(const AtomicString& name, const String& value, ExceptionCode&) const;
     bool remove(const AtomicString& name) const;
     void clear(ExceptionCode&) const;
+    void forEach(PassRefPtr<CSSVariablesMapForEachCallback>, ScriptValue* thisArg) const;
+    void forEach(PassRefPtr<CSSVariablesMapForEachCallback>, ScriptValue thisArg) const;
+    void forEach(PassRefPtr<CSSVariablesMapForEachCallback>) const;
 
     void clearStyleDeclaration() { m_styleDeclaration = 0; }