Removed the non-const version of PropertyReference::value()

third_party/WebKit/Source/core/animation/css/CSSAnimations.cpp

Index: third_party/WebKit/Source/core/animation/css/CSSAnimations.cpp
diff --git a/third_party/WebKit/Source/core/animation/css/CSSAnimations.cpp b/third_party/WebKit/Source/core/animation/css/CSSAnimations.cpp
index 6a5fe3c5ef753226321486530e28342f467e39f9..e43ed937975c362dc30a92c798e6df95cc720a84 100644
--- a/third_party/WebKit/Source/core/animation/css/CSSAnimations.cpp
+++ b/third_party/WebKit/Source/core/animation/css/CSSAnimations.cpp
@@ -91,7 +91,7 @@ static StringKeyframeEffectModel* createKeyframeEffectModel(StyleResolver* resol
             CSSPropertyID property = properties.propertyAt(j).id();
             specifiedPropertiesForUseCounter.add(property);
             if (property == CSSPropertyAnimationTimingFunction) {
-                CSSValue* value = properties.propertyAt(j).value();
+                const CSSValue* value = properties.propertyAt(j).value();
                 RefPtr<TimingFunction> timingFunction;
                 if (value->isInheritedValue() && parentStyle->animations()) {
                     timingFunction = parentStyle->animations()->timingFunctionList()[0];