Add SVGTests attrs to SVGSMILElement to support SVGDiscardElement

Source/core/svg/SVGAnimationElement.h

Index: Source/core/svg/SVGAnimationElement.h
diff --git a/Source/core/svg/SVGAnimationElement.h b/Source/core/svg/SVGAnimationElement.h
index abdffae12d37ca4b4daf35e65a9e0cf49c5b719e..d3daacdd4f4ca2c7c2fa8986d1f0f1af7dc9d186 100644
--- a/Source/core/svg/SVGAnimationElement.h
+++ b/Source/core/svg/SVGAnimationElement.h
@@ -26,7 +26,6 @@
 #define SVGAnimationElement_h
 
 #include "core/svg/SVGAnimatedBoolean.h"
-#include "core/svg/SVGTests.h"
 #include "core/svg/animation/SVGSMILElement.h"
 #include "platform/animation/UnitBezier.h"
 #include "wtf/Functional.h"
@@ -57,8 +56,7 @@ enum CalcMode {
     CalcModeSpline
 };
 
-class SVGAnimationElement : public SVGSMILElement,
-                            public SVGTests {
+class SVGAnimationElement : public SVGSMILElement {
 public:
     // SVGAnimationElement
     float getStartTime() const;