Make SVGLengthMode an enum class

Source/core/svg/SVGAnimatedTypeAnimator.cpp

Index: Source/core/svg/SVGAnimatedTypeAnimator.cpp
diff --git a/Source/core/svg/SVGAnimatedTypeAnimator.cpp b/Source/core/svg/SVGAnimatedTypeAnimator.cpp
index b6e5694f09196ad81977d3e95684aa69f213a6e9..b30cff9a17f1022673d3b15effd4bb0c07557d2c 100644
--- a/Source/core/svg/SVGAnimatedTypeAnimator.cpp
+++ b/Source/core/svg/SVGAnimatedTypeAnimator.cpp
@@ -104,12 +104,12 @@ PassRefPtrWillBeRawPtr<SVGPropertyBase> SVGAnimatedTypeAnimator::createPropertyF
         return property.release();
     }
     case AnimatedLength: {
-        RefPtrWillBeRawPtr<SVGLength> property = SVGLength::create(LengthModeOther);
+        RefPtrWillBeRawPtr<SVGLength> property = SVGLength::create();
         property->setValueAsString(value, IGNORE_EXCEPTION);
         return property.release();
     }
     case AnimatedLengthList: {
-        RefPtrWillBeRawPtr<SVGLengthList> property = SVGLengthList::create(LengthModeOther);
+        RefPtrWillBeRawPtr<SVGLengthList> property = SVGLengthList::create();
         property->setValueAsString(value, IGNORE_EXCEPTION);
         return property.release();
     }