Oilpan: Move core/clipboard/ to oilpan's heap

Source/core/page/DragState.h

Index: Source/core/page/DragState.h
diff --git a/Source/core/page/DragState.h b/Source/core/page/DragState.h
index 6b8665771701fca6bc5cf72d6a3afb2220b26d78..28083ed7710ff5f08b3c467bb0f0c0b247a2060e 100644
--- a/Source/core/page/DragState.h
+++ b/Source/core/page/DragState.h
@@ -35,14 +35,19 @@ namespace WebCore {
 class Clipboard;
 class Node;
 
-struct DragState {
+class DragState : public RefCountedWillBeGarbageCollectedFinalized<DragState> {
     WTF_MAKE_NONCOPYABLE(DragState);
-    WTF_MAKE_FAST_ALLOCATED;
+    DECLARE_GC_INFO;
 public:
     DragState() { }
     RefPtr<Node> m_dragSrc; // element that may be a drag source, for the current mouse gesture
     DragSourceAction m_dragType;
-    RefPtr<Clipboard> m_dragClipboard; // used on only the source side of dragging
+    RefPtrWillBeMember<Clipboard> m_dragClipboard; // used on only the source side of dragging
+
+    void trace(Visitor* visitor)
+    {
+        visitor->trace(m_dragClipboard);
+    }
 };
 
 } // namespace WebCore