SVG: SVGAnimateElement should not cache |m_animatedElements|

Source/core/svg/SVGUseElement.cpp

Index: Source/core/svg/SVGUseElement.cpp
diff --git a/Source/core/svg/SVGUseElement.cpp b/Source/core/svg/SVGUseElement.cpp
index 834dae3f388245f2708a391447448c2590af45e8..98994321bb8f31b22469b2107a18abc5691c5d9c 100644
--- a/Source/core/svg/SVGUseElement.cpp
+++ b/Source/core/svg/SVGUseElement.cpp
@@ -45,6 +45,7 @@
 
 namespace WebCore {
 
+
 inline SVGUseElement::SVGUseElement(Document& document, bool wasInsertedByParser)
     : SVGGraphicsElement(SVGNames::useTag, document)
     , SVGURIReference(this)
@@ -370,6 +371,18 @@ void SVGUseElement::buildPendingResource()
     ASSERT(!m_needsShadowTreeRecreation);
 }
 
+namespace {
+
+void restartSMILAnimationsForShadowTreeElements(SVGElement* shadowTreeTargetElement)
+{
+    shadowTreeTargetElement->document().accessSVGExtensions().rebuildSMILElementReferencesForTarget(shadowTreeTargetElement);
+
+    for (SVGElement* child = Traversal<SVGElement>::firstChild(*shadowTreeTargetElement); child; child = Traversal<SVGElement>::nextSibling(*child))
+        restartSMILAnimationsForShadowTreeElements(child);
+}
+
+} // namespace
+
 void SVGUseElement::buildShadowAndInstanceTree(SVGElement* target)
 {
     ASSERT(!m_targetElementInstance);
@@ -457,6 +470,9 @@ void SVGUseElement::buildShadowAndInstanceTree(SVGElement* target)
 
     // Update relative length information.
     updateRelativeLengthsInformation();
+
+    // SMIL animations need to be restarted in order to include elements inside new shadow tree.
+    restartSMILAnimationsForShadowTreeElements(shadowTreeTargetElement);
 }
 
 RenderObject* SVGUseElement::createRenderer(RenderStyle*)