Perf Tryjob: CSSValue refactor step 1

Source/core/editing/markup.cpp

Index: Source/core/editing/markup.cpp
diff --git a/Source/core/editing/markup.cpp b/Source/core/editing/markup.cpp
index 9ca18762c0c78e0c08b4100175312fc098b5a4ad..38957c13cee4f019d96453b294e38b3712d033d2 100644
--- a/Source/core/editing/markup.cpp
+++ b/Source/core/editing/markup.cpp
@@ -162,12 +162,12 @@ bool propertyMissingOrEqualToNone(StylePropertySet* style, CSSPropertyID propert
 {
     if (!style)
         return false;
-    RefPtrWillBeRawPtr<CSSValue> value = style->getPropertyCSSValue(propertyID);
+    NullableCSSValue value = style->getPropertyCSSValue(propertyID);
     if (!value)
         return true;
     if (!value->isPrimitiveValue())
         return false;
-    return toCSSPrimitiveValue(value.get())->getValueID() == CSSValueNone;
+    return toCSSPrimitiveValue(value)->getValueID() == CSSValueNone;
 }
 
 static bool isPresentationalHTMLElement(const Node* node)