Oilpan: move DOM string collection objects to the Oilpan heap.

Source/core/dom/DatasetDOMStringMap.h

 /*
  * Copyright (C) 2010 Apple 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:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. 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/dom/DOMStringMap.h"
 #include "wtf/PassOwnPtr.h"
 
 namespace WebCore {
 
 class Element;
 class ExceptionState;
 
 class DatasetDOMStringMap FINAL : public DOMStringMap {
 public:
-    static PassOwnPtr<DatasetDOMStringMap> create(Element* element)
+    static PassOwnPtrWillBeRawPtr<DatasetDOMStringMap> create(Element* element)
     {
-        return adoptPtr(new DatasetDOMStringMap(element));
+        return adoptPtrWillBeNoop(new DatasetDOMStringMap(element));
     }
 
+#if !ENABLE(OILPAN)
     virtual void ref() OVERRIDE;
     virtual void deref() OVERRIDE;
+#endif
 
     virtual void getNames(Vector<String>&) OVERRIDE;
     virtual String item(const String& name) OVERRIDE;
     virtual bool contains(const String& name) OVERRIDE;
     virtual void setItem(const String& name, const String& value, ExceptionState&) OVERRIDE;
     virtual bool deleteItem(const String& name) OVERRIDE;
 
     virtual Element* element() OVERRIDE { return m_element; }
 
+    virtual void trace(Visitor*) OVERRIDE;
+
 private:
     explicit DatasetDOMStringMap(Element* element)
         : m_element(element)
     {
     }
 
     Element* m_element;

[Erik Corry, 2014/04/29 07:55:49]

Should this not be a Member?

[haraken, 2014/04/29 08:00:02]

We can't use a Member to the Node hierarchy until mads lands his next change
(i.e., make all directions traceable in the Node hierarchy).

[sof, 2014/04/29 08:06:38]

ok, I thought we already had those (cf. TextTrackList::m_owner)?

It was an oversight not to use RawPtrWillBeMember<> here for m_element; will
fix.

[Mads Ager (chromium), 2014/04/29 08:52:09]

We can use a Member here and trace it. We *cannot* replace any RefPtrs with
Members at this point. Right now a Member does not keep the hierarchy alive.
That is still managed by ref counting. Using a Member here does not change ref
counts and therefore would work (but would not keep the tree alive, only that
one element). I'm working on making sure that Members keep the entire tree
alive.

So, turning raw pointers into Members is fine. However, it does not give the
correct life-time guarantees yet. Turning RefPtrs into Members will lead to
premature tear down of parts of the Node hierarchy and therefore cannot be done
at this point.

 };
 
 } // namespace WebCore
 
 #endif // DatasetDOMStringMap_h