Remove leak of objects between isolated worlds on custom events.

Source/core/dom/PopStateEvent.cpp

Index: Source/core/dom/PopStateEvent.cpp
diff --git a/Source/core/dom/PopStateEvent.cpp b/Source/core/dom/PopStateEvent.cpp
index 072d28ba177377fa4f55318709e6094a4e0b8980..78456c830c6a551a5fe4f125c7270b30f676243b 100644
--- a/Source/core/dom/PopStateEvent.cpp
+++ b/Source/core/dom/PopStateEvent.cpp
@@ -33,10 +33,6 @@
 
 namespace WebCore {
 
-PopStateEventInit::PopStateEventInit()
-{
-}
-
 PopStateEvent::PopStateEvent()
     : Event(eventNames().popstateEvent, false, true)
     , m_serializedState(0)
@@ -47,7 +43,6 @@ PopStateEvent::PopStateEvent()
 
 PopStateEvent::PopStateEvent(const AtomicString& type, const PopStateEventInit& initializer)
     : Event(type, initializer)
-    , m_state(initializer.state)
     , m_serializedState(0)
     , m_history(0)
 {