Properly retain non-node event listeners.

Source/WebCore/bindings/dart/DartDOMData.h

Index: Source/WebCore/bindings/dart/DartDOMData.h
diff --git a/Source/WebCore/bindings/dart/DartDOMData.h b/Source/WebCore/bindings/dart/DartDOMData.h
index 868cc737012825ded15232eb68f0d68330165f12..ae90fc1f7f1bed645df93c102791f499ee6b35cc 100644
--- a/Source/WebCore/bindings/dart/DartDOMData.h
+++ b/Source/WebCore/bindings/dart/DartDOMData.h
@@ -45,6 +45,7 @@ class DOMWindow;
 class DartApplicationLoader;
 class DartEventListener;
 class DartWeakCallback;
+class EventTarget;
 class MessagePort;
 class Node;
 class ScriptExecutionContext;
@@ -53,6 +54,7 @@ typedef HashMap<Node*, Dart_Handle> DartDOMNodeMap;
 typedef HashMap<void*, Dart_Handle> DartDOMObjectMap;
 typedef HashMap<MessagePort*, Dart_Handle> DartMessagePortMap;
 typedef HashMap<ActiveDOMObject*, Dart_Handle> DartActiveDOMObjectMap;
+typedef HashMap<EventTarget*, Dart_Handle> DartEventTargetMap;
 typedef HashSet<DartWeakCallback*> DartWeakCallbacks;
 
 class DartDOMData {
@@ -70,6 +72,7 @@ public:
     DartDOMObjectMap* objectMap() { return &m_objectMap; }
     DartMessagePortMap* messagePortMap() { return &m_messagePortMap; }
     DartActiveDOMObjectMap* activeObjectMap() { return &m_activeObjectMap; }
+    DartEventTargetMap* eventTargetMap() { return &m_eventTargetMap; }
     DartWeakCallbacks* weakCallbacks() { return &m_weakCallbacks; }
 
 private:
@@ -82,6 +85,7 @@ private:
     DartDOMObjectMap m_objectMap;
     DartMessagePortMap m_messagePortMap;
     DartActiveDOMObjectMap m_activeObjectMap;
+    DartEventTargetMap m_eventTargetMap;
     DartWeakCallbacks m_weakCallbacks;
 };