Clean up after getPropertyCSSValue

Source/core/css/CSSFilterValue.h

Index: Source/core/css/CSSFilterValue.h
diff --git a/Source/core/css/CSSFilterValue.h b/Source/core/css/CSSFilterValue.h
index db12cc6755d59f528094d1636975df84012b3930..51307c41671378a1c08c7b53edb74bd7db59b24f 100644
--- a/Source/core/css/CSSFilterValue.h
+++ b/Source/core/css/CSSFilterValue.h
@@ -61,15 +61,12 @@ public:
 
     FilterOperationType operationType() const { return m_type; }
 
-    PassRefPtrWillBeRawPtr<CSSFilterValue> cloneForCSSOM() const;
-
     bool equals(const CSSFilterValue&) const;
 
     void traceAfterDispatch(Visitor* visitor) { CSSValueList::traceAfterDispatch(visitor); }
 
 private:
     explicit CSSFilterValue(FilterOperationType);
-    explicit CSSFilterValue(const CSSFilterValue& cloneFrom);
 
     FilterOperationType m_type;
 };