CSSValue Immediates: Replace CSSPrimitiveValue usage with const references

Source/core/css/CSSBorderImageSliceValue.h

Index: Source/core/css/CSSBorderImageSliceValue.h
diff --git a/Source/core/css/CSSBorderImageSliceValue.h b/Source/core/css/CSSBorderImageSliceValue.h
index 6fd9856fedf668d49f4a2c4f0cbc760a897cc1e0..f4ecad8a974b97a27946ebddfbac5a6c7bf587c4 100644
--- a/Source/core/css/CSSBorderImageSliceValue.h
+++ b/Source/core/css/CSSBorderImageSliceValue.h
@@ -34,7 +34,7 @@ namespace blink {
 
 class CSSBorderImageSliceValue : public CSSValueObject {
 public:
-    static PassRefPtrWillBeRawPtr<CSSBorderImageSliceValue> create(CSSPrimitiveValue slices, bool fill)
+    static PassRefPtrWillBeRawPtr<CSSBorderImageSliceValue> create(const CSSPrimitiveValue& slices, bool fill)
     {
         return adoptRefWillBeNoop(new CSSBorderImageSliceValue(slices, fill));
     }
@@ -53,7 +53,7 @@ public:
     bool m_fill;
 
 private:
-    CSSBorderImageSliceValue(CSSPrimitiveValue slices, bool fill);
+    CSSBorderImageSliceValue(const CSSPrimitiveValue& slices, bool fill);
 };
 
 DEFINE_CSS_VALUE_TYPE_CASTS(CSSBorderImageSliceValue, isBorderImageSliceValue());