CSSValue Immediates: Replace CSSValue usage with const references

Source/core/animation/animatable/AnimatableImage.cpp

Index: Source/core/animation/animatable/AnimatableImage.cpp
diff --git a/Source/core/animation/animatable/AnimatableImage.cpp b/Source/core/animation/animatable/AnimatableImage.cpp
index 4e0b740af11c27315df552fc4c8171029baff145..9e157abb6ee80bd8c1ca47ab73bd59acc99146a3 100644
--- a/Source/core/animation/animatable/AnimatableImage.cpp
+++ b/Source/core/animation/animatable/AnimatableImage.cpp
@@ -52,8 +52,8 @@ PassRefPtrWillBeRawPtr<AnimatableValue> AnimatableImage::interpolateTo(const Ani
     if (fraction <= 0 || fraction >= 1 || usesDefaultInterpolationWith(value))
         return defaultInterpolateTo(this, value, fraction);
 
-    CSSValue fromValue = toCSSValue();
-    CSSValue toValue = toAnimatableImage(value)->toCSSValue();
+    const CSSValue& fromValue = toCSSValue();
+    const CSSValue& toValue = toAnimatableImage(value)->toCSSValue();
 
     RefPtrWillBeRawPtr<CSSCrossfadeValue> crossfadeValue = CSSCrossfadeValue::create(fromValue, toValue);
     crossfadeValue->setPercentage(CSSPrimitiveValue::create(fraction, CSSPrimitiveValue::CSS_NUMBER));