Iron out some kinks in SVG IDL files

Source/core/svg/SVGAnimationElement.cpp

Index: Source/core/svg/SVGAnimationElement.cpp
diff --git a/Source/core/svg/SVGAnimationElement.cpp b/Source/core/svg/SVGAnimationElement.cpp
index 2a125ea0690bf40d9817455da47514a73b0aba3b..e920868f82869963ad5f904f1140e6b728d4c0fd 100644
--- a/Source/core/svg/SVGAnimationElement.cpp
+++ b/Source/core/svg/SVGAnimationElement.cpp
@@ -258,7 +258,7 @@ void SVGAnimationElement::beginElement()
 
 void SVGAnimationElement::beginElementAt(float offset)
 {
-    if (std::isnan(offset))
+    if (!std::isfinite(offset))
         return;
     SMILTime elapsed = this->elapsed();
     addBeginTime(elapsed, elapsed + offset, SMILTimeWithOrigin::ScriptOrigin);
@@ -271,7 +271,7 @@ void SVGAnimationElement::endElement()
 
 void SVGAnimationElement::endElementAt(float offset)
 {
-    if (std::isnan(offset))
+    if (!std::isfinite(offset))
         return;
     SMILTime elapsed = this->elapsed();
     addEndTime(elapsed, elapsed + offset, SMILTimeWithOrigin::ScriptOrigin);