Enable Oilpan for core/clipboard/

Source/web/WebViewImpl.h

 /*
  * Copyright (C) 2010 Google 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 629 matching lines @@
     IntSize m_maxAutoSize;
 
     OwnPtrWillBePersistent<Page> m_page;
 
     // An object that can be used to manipulate m_page->settings() without linking
     // against WebCore. This is lazily allocated the first time GetWebSettings()
     // is called.
     OwnPtr<WebSettingsImpl> m_webSettings;
 
     // A copy of the web drop data object we received from the browser.
-    RefPtrWillBePersistent<DataObject> m_currentDragData;
+    Persistent<DataObject> m_currentDragData;
 
     // The point relative to the client area where the mouse was last pressed
     // down. This is used by the drag client to determine what was under the
     // mouse when the drag was initiated. We need to track this here in
     // WebViewImpl since DragClient::startDrag does not pass the position the
     // mouse was at when the drag was initiated, only the current point, which
     // can be misleading as it is usually not over the element the user actually
     // dragged by the time a drag is initiated.
     WebPoint m_lastMouseDownPoint;
 
@@ skipping 104 matching lines @@
 };
 
 DEFINE_TYPE_CASTS(WebViewImpl, WebWidget, widget, widget->isWebView(), widget.isWebView());
 // We have no ways to check if the specified WebView is an instance of
 // WebViewImpl because WebViewImpl is the only implementation of WebView.
 DEFINE_TYPE_CASTS(WebViewImpl, WebView, webView, true, true);
 
 } // namespace blink
 
 #endif