CSSValue Immediates: Replace CSSPrimitiveValue usage with const references

Source/core/css/CSSShadowValue.h

Index: Source/core/css/CSSShadowValue.h
diff --git a/Source/core/css/CSSShadowValue.h b/Source/core/css/CSSShadowValue.h
index 7e92a680aab3a65067cae327186d5828afcd6814..fdec5a1799c8c4b8d0fe2f1d8147c365b20333e7 100644
--- a/Source/core/css/CSSShadowValue.h
+++ b/Source/core/css/CSSShadowValue.h
@@ -33,12 +33,12 @@ class CSSPrimitiveValue;
 // Used for text-shadow and box-shadow
 class CORE_EXPORT CSSShadowValue : public CSSValueObject {
 public:
-    static PassRefPtrWillBeRawPtr<CSSShadowValue> create(NullableCSSValue x,
-        NullableCSSValue y,
-        NullableCSSValue blur,
-        NullableCSSValue spread,
-        NullableCSSValue style,
-        NullableCSSValue color)
+    static PassRefPtrWillBeRawPtr<CSSShadowValue> create(const NullableCSSValue& x,
+        const NullableCSSValue& y,
+        const NullableCSSValue& blur,
+        const NullableCSSValue& spread,
+        const NullableCSSValue& style,
+        const NullableCSSValue& color)
     {
         return adoptRefWillBeNoop(new CSSShadowValue(x, y, blur, spread, style, color));
     }
@@ -57,12 +57,12 @@ public:
     DECLARE_TRACE_AFTER_DISPATCH();
 
 private:
-    CSSShadowValue(NullableCSSValue x,
-        NullableCSSValue y,
-        NullableCSSValue blur,
-        NullableCSSValue spread,
-        NullableCSSValue style,
-        NullableCSSValue color);
+    CSSShadowValue(const NullableCSSValue& x,
+        const NullableCSSValue& y,
+        const NullableCSSValue& blur,
+        const NullableCSSValue& spread,
+        const NullableCSSValue& style,
+        const NullableCSSValue& color);
 };
 
 DEFINE_CSS_VALUE_TYPE_CASTS(CSSShadowValue, isShadowValue());