CSSValue Immediates: Replace CSSValue usage with const references

Source/core/css/CSSCrossfadeValue.cpp

Index: Source/core/css/CSSCrossfadeValue.cpp
diff --git a/Source/core/css/CSSCrossfadeValue.cpp b/Source/core/css/CSSCrossfadeValue.cpp
index f484eb7e92e6ce2e77e11a3f2c0262d5762b4a85..57d0a8d0b0383721f077bd507925c453f726a057 100644
--- a/Source/core/css/CSSCrossfadeValue.cpp
+++ b/Source/core/css/CSSCrossfadeValue.cpp
@@ -34,7 +34,7 @@
 
 namespace blink {
 
-static bool subimageIsPending(CSSValue value)
+static bool subimageIsPending(const CSSValue& value)
 {
     if (value.isImageValue())
         return toCSSImageValue(value).cachedOrPendingImage()->isPendingImage();
@@ -47,7 +47,7 @@ static bool subimageIsPending(CSSValue value)
     return false;
 }
 
-static bool subimageKnownToBeOpaque(CSSValue value, const LayoutObject* layoutObject)
+static bool subimageKnownToBeOpaque(const CSSValue& value, const LayoutObject* layoutObject)
 {
     if (value.isImageValue())
         return toCSSImageValue(value).knownToBeOpaque(layoutObject);
@@ -60,7 +60,7 @@ static bool subimageKnownToBeOpaque(CSSValue value, const LayoutObject* layoutOb
     return false;
 }
 
-static ImageResource* cachedImageForCSSValue(CSSValue value, Document* document)
+static ImageResource* cachedImageForCSSValue(const CSSValue& value, Document* document)
 {
     if (value.isImageValue()) {
         StyleFetchedImage* styleImageResource = toCSSImageValue(value).cachedImage(document);