Introduce few const getters for dom classes

third_party/WebKit/Source/core/events/EventTarget.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008 Apple Inc. All rights reserved.
  * Copyright (C) 2006 Alexey Proskuryakov (ap@webkit.org)
  *           (C) 2007, 2008 Nikolas Zimmermann <zimmermann@kde.org>
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
@@ skipping 154 matching lines @@
     virtual bool keepEventInNode(Event*) { return false; }
 
 protected:
     EventTarget();
 
     virtual bool addEventListenerInternal(const AtomicString& eventType, EventListener*, const EventListenerOptions&);
     virtual bool removeEventListenerInternal(const AtomicString& eventType, EventListener*, const EventListenerOptions&);
     virtual DispatchEventResult dispatchEventInternal(Event*);
 
     // Subclasses should likely not override these themselves; instead, they should subclass EventTargetWithInlineData.
-    virtual EventTargetData* eventTargetData() = 0;
+    virtual EventTargetData* eventTargetData() const = 0;
     virtual EventTargetData& ensureEventTargetData() = 0;
 
 private:
 #if !ENABLE(OILPAN)
     // Subclasses should likely not override these themselves; instead, they should use the REFCOUNTED_EVENT_TARGET() macro.
     virtual void refEventTarget() = 0;
     virtual void derefEventTarget() = 0;
 #endif
 
     LocalDOMWindow* executingWindow();
@@ skipping 11 matching lines @@
 // EventTargetWithInlineData::m_eventTargetData and store it to a Member etc.
 class GC_PLUGIN_IGNORE("513199") CORE_EXPORT EventTargetWithInlineData : public EventTarget {
 public:
     DEFINE_INLINE_VIRTUAL_TRACE()
     {
         visitor->trace(m_eventTargetData);
         EventTarget::trace(visitor);
     }
 
 protected:
-    EventTargetData* eventTargetData() final { return &m_eventTargetData; }
+    EventTargetData* eventTargetData() const final
+    {
+        return const_cast<EventTargetData*>(&m_eventTargetData);
+    }
+
     EventTargetData& ensureEventTargetData() final { return m_eventTargetData; }
 
 private:
     EventTargetData m_eventTargetData;
 };
 
 // Base class for classes that wish to inherit from RefCountedGarbageCollected (in non-Oilpan world) and
 // EventTargetWithInlineData (in both worlds). For details about how to use this class template, see the comments for
 // EventTargetWithInlineData above.
 //
@@ skipping 94 matching lines @@
     using baseClass::deref; \
 private: \
     void refEventTarget() final { ref(); } \
     void derefEventTarget() final { deref(); } \
     typedef int thisIsHereToForceASemiColonAfterThisEventTargetMacro
 #define REFCOUNTED_EVENT_TARGET(baseClass) DEFINE_EVENT_TARGET_REFCOUNTING(RefCounted<baseClass>)
 #define REFCOUNTED_GARBAGE_COLLECTED_EVENT_TARGET(baseClass) DEFINE_EVENT_TARGET_REFCOUNTING(RefCountedGarbageCollected<baseClass>)
 #endif // ENABLE(OILPAN)
 
 #endif // EventTarget_h