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

Source/core/page/DragController.h

 /*
  * Copyright (C) 2007, 2009 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 21 matching lines @@
 #include "wtf/Forward.h"
 
 namespace WebCore {
 
     class Clipboard;
     class Document;
     class DragClient;
     class DragData;
     class DragImage;
     struct DragSession;
-    struct DragState;
+    class DragState;
     class Element;
     class Frame;
     class FrameSelection;
     class HTMLInputElement;
     class Image;
     class IntRect;
     class Node;
     class Page;
     class PlatformMouseEvent;
     class Range;
@@ skipping 51 matching lines @@
         RefPtr<HTMLInputElement> m_fileInputElementUnderMouse;
         bool m_documentIsHandlingDrag;
 
         DragDestinationAction m_dragDestinationAction;
         bool m_didInitiateDrag;
     };
 
 }
 
 #endif