Add [WillBeGarbageCollected] to Event.idl

Source/core/events/GestureEvent.h

 /*
  * Copyright (C) 2012 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  *  * Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  *  * Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 18 matching lines @@
 #include "core/events/EventDispatcher.h"
 #include "core/events/MouseRelatedEvent.h"
 #include "platform/PlatformGestureEvent.h"
 
 namespace WebCore {
 
 class GestureEvent FINAL : public MouseRelatedEvent {
 public:
     virtual ~GestureEvent() { }
 
-    static PassRefPtr<GestureEvent> create(PassRefPtr<AbstractView>, const PlatformGestureEvent&);
+    static PassRefPtrWillBeRawPtr<GestureEvent> create(PassRefPtr<AbstractView>, const PlatformGestureEvent&);
 
     virtual bool isGestureEvent() const OVERRIDE;
 
     virtual const AtomicString& interfaceName() const OVERRIDE;
 
     float deltaX() const { return m_deltaX; }
     float deltaY() const { return m_deltaY; }
 
     virtual void trace(Visitor*) OVERRIDE;
 
@@ skipping 18 matching lines @@
     GestureEvent* event() const;
 
     virtual bool dispatchEvent(EventDispatcher*) const OVERRIDE;
 };
 
 DEFINE_EVENT_TYPE_CASTS(GestureEvent);
 
 } // namespace WebCore
 
 #endif // GestureEvent_h