Change RefPtr<DOMWrapperWorld> that causes reference cycles to DOMWrapperWorld*

Source/bindings/v8/V8AbstractEventListener.h

Index: Source/bindings/v8/V8AbstractEventListener.h
diff --git a/Source/bindings/v8/V8AbstractEventListener.h b/Source/bindings/v8/V8AbstractEventListener.h
index 07e42832ebd5479ccff48d1c2b85a87eba8a5668..bf5b3a0a6c5deb18451b11e973cfe791f4041f5d 100644
--- a/Source/bindings/v8/V8AbstractEventListener.h
+++ b/Source/bindings/v8/V8AbstractEventListener.h
@@ -109,11 +109,11 @@ namespace WebCore {
         }
 
         virtual bool belongsToTheCurrentWorld() const OVERRIDE FINAL;
-        virtual DOMWrapperWorld* world() const OVERRIDE FINAL { return m_world.get(); }
+        virtual DOMWrapperWorld* world() const OVERRIDE FINAL { return m_world; }
         v8::Isolate* isolate() const { return m_isolate; }
 
     protected:
-        V8AbstractEventListener(bool isAttribute, PassRefPtr<DOMWrapperWorld>, v8::Isolate*);
+        V8AbstractEventListener(bool isAttribute, DOMWrapperWorld*, v8::Isolate*);
 
         virtual void prepareListenerObject(ExecutionContext*) { }
 
@@ -139,7 +139,7 @@ namespace WebCore {
         // Indicates if this is an HTML type listener.
         bool m_isAttribute;
 
-        RefPtr<DOMWrapperWorld> m_world;
+        DOMWrapperWorld* m_world;
         v8::Isolate* m_isolate;
     };