CSSValue Immediates: Replace CSSValue usage with const references

Source/core/css/resolver/StyleResolver.cpp

Index: Source/core/css/resolver/StyleResolver.cpp
diff --git a/Source/core/css/resolver/StyleResolver.cpp b/Source/core/css/resolver/StyleResolver.cpp
index 26002b980722fe06a4318b784865a91cf3d9db16..21dae32c7f7b4e4ed71718410883f8ea441b0600 100644
--- a/Source/core/css/resolver/StyleResolver.cpp
+++ b/Source/core/css/resolver/StyleResolver.cpp
@@ -639,14 +639,14 @@ PassRefPtr<ComputedStyle> StyleResolver::styleForElement(Element* element, const
 
 // This function is used by the WebAnimations JavaScript API method animate().
 // FIXME: Remove this when animate() switches away from resolution-dependent parsing.
-PassRefPtrWillBeRawPtr<AnimatableValue> StyleResolver::createAnimatableValueSnapshot(Element& element, const ComputedStyle* baseStyle, CSSPropertyID property, NullableCSSValue value)
+PassRefPtrWillBeRawPtr<AnimatableValue> StyleResolver::createAnimatableValueSnapshot(Element& element, const ComputedStyle* baseStyle, CSSPropertyID property, const NullableCSSValue& value)
 {
     StyleResolverState state(element.document(), &element);
     state.setStyle(baseStyle ? ComputedStyle::clone(*baseStyle) : ComputedStyle::create());
     return createAnimatableValueSnapshot(state, property, value);
 }
 
-PassRefPtrWillBeRawPtr<AnimatableValue> StyleResolver::createAnimatableValueSnapshot(StyleResolverState& state, CSSPropertyID property, NullableCSSValue value)
+PassRefPtrWillBeRawPtr<AnimatableValue> StyleResolver::createAnimatableValueSnapshot(StyleResolverState& state, CSSPropertyID property, const NullableCSSValue& value)
 {
     if (value) {
         StyleBuilder::applyProperty(property, state, *value);