Add [WillBeGarbageCollected] to Event.idl

Source/core/events/PopStateEvent.h

Index: Source/core/events/PopStateEvent.h
diff --git a/Source/core/events/PopStateEvent.h b/Source/core/events/PopStateEvent.h
index b222df9b83efd466052e08713d23ab27247efd2f..8b8cf99562537f314738f90b3e23438d46c59df9 100644
--- a/Source/core/events/PopStateEvent.h
+++ b/Source/core/events/PopStateEvent.h
@@ -40,9 +40,9 @@ typedef EventInit PopStateEventInit;
 class PopStateEvent FINAL : public Event {
 public:
     virtual ~PopStateEvent();
-    static PassRefPtr<PopStateEvent> create();
-    static PassRefPtr<PopStateEvent> create(PassRefPtr<SerializedScriptValue>, PassRefPtrWillBeRawPtr<History>);
-    static PassRefPtr<PopStateEvent> create(const AtomicString&, const PopStateEventInit&);
+    static PassRefPtrWillBeRawPtr<PopStateEvent> create();
+    static PassRefPtrWillBeRawPtr<PopStateEvent> create(PassRefPtr<SerializedScriptValue>, PassRefPtrWillBeRawPtr<History>);
+    static PassRefPtrWillBeRawPtr<PopStateEvent> create(const AtomicString&, const PopStateEventInit&);
 
     SerializedScriptValue* serializedState() const { return m_serializedState.get(); }
     void setSerializedState(PassRefPtr<SerializedScriptValue> state)