Lock animated property type of result animation during processing

third_party/WebKit/Source/core/svg/SVGAnimateElement.h

Index: third_party/WebKit/Source/core/svg/SVGAnimateElement.h
diff --git a/third_party/WebKit/Source/core/svg/SVGAnimateElement.h b/third_party/WebKit/Source/core/svg/SVGAnimateElement.h
index 7a407811177efae3ef9c20d11151ff7e48fc634b..a0df9a97d56aa94ef342c788451202358e93e11d 100644
--- a/third_party/WebKit/Source/core/svg/SVGAnimateElement.h
+++ b/third_party/WebKit/Source/core/svg/SVGAnimateElement.h
@@ -53,6 +53,9 @@ public:
 protected:
     SVGAnimateElement(const QualifiedName&, Document&);
 
+    void lockAnimatedType() final { DCHECK(!m_animatedPropertyLocked); m_animatedPropertyLocked = true; }
+    void unlockAnimatedType() final { DCHECK(m_animatedPropertyLocked); m_animatedPropertyLocked = false; }
+
     void resetAnimatedType() final;
     void clearAnimatedType() final;
 
@@ -80,6 +83,8 @@ private:
     Member<SVGPropertyBase> m_animatedProperty;
 
     SVGAnimatedTypeAnimator m_animator;
+
+    bool m_animatedPropertyLocked;
 };
 
 inline bool isSVGAnimateElement(const SVGElement& element)