SVG: SVGAnimateElement should not cache |m_animatedElements|

Source/core/svg/SVGElementInstance.cpp

Index: Source/core/svg/SVGElementInstance.cpp
diff --git a/Source/core/svg/SVGElementInstance.cpp b/Source/core/svg/SVGElementInstance.cpp
index 752f4826415236708ef14fa9094bb23d8ecf8712..869ab37bcb7239884f6e6a8164cb1b35eba2a72e 100644
--- a/Source/core/svg/SVGElementInstance.cpp
+++ b/Source/core/svg/SVGElementInstance.cpp
@@ -26,6 +26,7 @@
 #include "core/dom/ContainerNodeAlgorithms.h"
 #include "core/events/Event.h"
 #include "core/events/EventListener.h"
+#include "core/svg/SVGDocumentExtensions.h"
 #include "core/svg/SVGElement.h"
 #include "core/svg/SVGUseElement.h"
 
@@ -143,6 +144,9 @@ void SVGElementInstance::detach()
 
     m_shadowTreeElement = nullptr;
 
+    // SMIL animations need to be restarted in order to exclude |shadowTreeElement()|.
+    m_element->document().accessSVGExtensions().rebuildSMILElementReferencesForTarget(m_element.get());
+
     m_directUseElement = nullptr;
     m_correspondingUseElement = nullptr;
 
@@ -158,6 +162,8 @@ void SVGElementInstance::setShadowTreeElement(SVGElement* element)
     // Register as instance for passed element.
     m_element->mapInstanceToElement(shadowTreeElement());
 
+    // SMIL animations need to be restarted in order to include |shadowTreeElement()|.
+    m_element->document().accessSVGExtensions().rebuildSMILElementReferencesForTarget(m_element.get());
 }
 
 void SVGElementInstance::appendChild(PassRefPtr<SVGElementInstance> child)