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

Source/core/dom/DOMStringList.h

Index: Source/core/dom/DOMStringList.h
diff --git a/Source/core/dom/DOMStringList.h b/Source/core/dom/DOMStringList.h
index 44de3447398dc782141fbcb9f8c0031ab200022e..dd605cd3b567c626db1490f75639776c1d7eb1f4 100644
--- a/Source/core/dom/DOMStringList.h
+++ b/Source/core/dom/DOMStringList.h
@@ -27,6 +27,7 @@
 #define DOMStringList_h
 
 #include "bindings/v8/ScriptWrappable.h"
+#include "platform/heap/Handle.h"
 #include "wtf/PassRefPtr.h"
 #include "wtf/RefCounted.h"
 #include "wtf/Vector.h"
@@ -36,11 +37,11 @@ namespace WebCore {
 
 // FIXME: Some consumers of this class may benefit from lazily fetching items rather
 //        than creating the list statically as is currently the only option.
-class DOMStringList : public ScriptWrappable, public RefCounted<DOMStringList> {
+class DOMStringList FINAL : public RefCountedWillBeGarbageCollectedFinalized<DOMStringList>, public ScriptWrappable {
 public:
-    static PassRefPtr<DOMStringList> create()
+    static PassRefPtrWillBeRawPtr<DOMStringList> create()
     {
-        return adoptRef(new DOMStringList());
+        return adoptRefWillBeNoop(new DOMStringList());
     }
 
     bool isEmpty() const { return m_strings.isEmpty(); }
@@ -55,6 +56,8 @@ public:
 
     operator const Vector<String>&() const { return m_strings; }
 
+    void trace(Visitor*) { }
+
 private:
     DOMStringList()
     {