Generate toCSSFooValue() for CSSCanvasValue, CSSCrossfadeValue, CSSImageGeneratorValue, CSSImageVal…

Source/core/css/CSSToStyleMap.cpp

Index: Source/core/css/CSSToStyleMap.cpp
diff --git a/Source/core/css/CSSToStyleMap.cpp b/Source/core/css/CSSToStyleMap.cpp
index 76331f7e2bb51ff747b2f3d2c3ee518b230e49bd..4dacaa7b7123f4fdf45d732756ccc057fcc5c2bd 100644
--- a/Source/core/css/CSSToStyleMap.cpp
+++ b/Source/core/css/CSSToStyleMap.cpp
@@ -519,10 +519,10 @@ void CSSToStyleMap::mapAnimationTimingFunction(CSSAnimationData* animation, CSSV
     }
 
     if (value->isCubicBezierTimingFunctionValue()) {
-        CSSCubicBezierTimingFunctionValue* cubicTimingFunction = static_cast<CSSCubicBezierTimingFunctionValue*>(value);
+        CSSCubicBezierTimingFunctionValue* cubicTimingFunction = toCSSCubicBezierTimingFunctionValue(value);
         animation->setTimingFunction(CubicBezierTimingFunction::create(cubicTimingFunction->x1(), cubicTimingFunction->y1(), cubicTimingFunction->x2(), cubicTimingFunction->y2()));
     } else if (value->isStepsTimingFunctionValue()) {
-        CSSStepsTimingFunctionValue* stepsTimingFunction = static_cast<CSSStepsTimingFunctionValue*>(value);
+        CSSStepsTimingFunctionValue* stepsTimingFunction = toCSSStepsTimingFunctionValue(value);
         animation->setTimingFunction(StepsTimingFunction::create(stepsTimingFunction->numberOfSteps(), stepsTimingFunction->stepAtStart()));
     }
 }