Support event handling in SVG's use-element shadow trees

third_party/WebKit/Source/core/svg/SVGUseElement.cpp

Index: third_party/WebKit/Source/core/svg/SVGUseElement.cpp
diff --git a/third_party/WebKit/Source/core/svg/SVGUseElement.cpp b/third_party/WebKit/Source/core/svg/SVGUseElement.cpp
index 0c0d7c0bd3c5401c8e7e1d59916f6e39e5420b8d..2d62599715dd4a8b8b2e414497c51f6c929c8b51 100644
--- a/third_party/WebKit/Source/core/svg/SVGUseElement.cpp
+++ b/third_party/WebKit/Source/core/svg/SVGUseElement.cpp
@@ -441,8 +441,10 @@ void SVGUseElement::buildShadowAndInstanceTree(SVGElement& target) {
 
   addReferencesToFirstDegreeNestedUseElements(target);
 
-  if (instanceTreeIsLoading())
+  if (instanceTreeIsLoading()) {
+    cloneNonMarkupEventListeners();
     return;
+  }
 
   // Assure shadow tree building was successful.
   DCHECK(m_targetElementInstance);
@@ -462,6 +464,8 @@ void SVGUseElement::buildShadowAndInstanceTree(SVGElement& target) {
   m_targetElementInstance = toSVGElementOrDie(shadowRoot.firstChild());
   DCHECK_EQ(m_targetElementInstance->parentNode(), shadowRoot);
 
+  cloneNonMarkupEventListeners();
+
   // Update relative length information.
   updateRelativeLengthsInformation();
 }
@@ -535,6 +539,17 @@ void SVGUseElement::addReferencesToFirstDegreeNestedUseElements(
     addReferenceTo(useElement);
 }
 
+void SVGUseElement::cloneNonMarkupEventListeners() {
+  for (SVGElement& element :
+       Traversal<SVGElement>::descendantsOf(useShadowRoot())) {
+    if (EventTargetData* data =
+            element.correspondingElement()->eventTargetData()) {
+      data->eventListenerMap.copyEventListenersNotCreatedFromMarkupToTarget(
+          &element);
+    }
+  }
+}
+
 bool SVGUseElement::hasCycleUseReferencing(const SVGUseElement& use,
                                            const ContainerNode& targetInstance,
                                            SVGElement*& newTarget) const {