Have DataTransferItemList.add() methods return the added item

Source/core/platform/chromium/ChromiumDataObject.h

 /*
  * Copyright (c) 2008, 2009, 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 44 matching lines @@
     static PassRefPtr<ChromiumDataObject> create();
 
     PassRefPtr<ChromiumDataObject> copy() const;
 
     // DataTransferItemList support.
     size_t length() const;
     PassRefPtr<ChromiumDataObjectItem> item(unsigned long index);
     // FIXME: Implement V8DataTransferItemList::indexedPropertyDeleter to get this called.
     void deleteItem(unsigned long index);
     void clearAll();
-    void add(const String& data, const String& type, ExceptionState&);
-    void add(PassRefPtr<File>, ScriptExecutionContext*);
+    PassRefPtr<ChromiumDataObjectItem> add(const String& data, const String& type, ExceptionState&);
+    PassRefPtr<ChromiumDataObjectItem> add(PassRefPtr<File>, ScriptExecutionContext*);
 
     // WebCore helpers.
     void clearData(const String& type);
     void clearAllExceptFiles();
 
     ListHashSet<String> types() const;
     String getData(const String& type) const;
     bool setData(const String& type, const String& data);
 
     void urlAndTitle(String& url, String* title = 0) const;
@@ skipping 22 matching lines @@
 
     Vector<RefPtr<ChromiumDataObjectItem> > m_itemList;
 
     // State of Shift/Ctrl/Alt/Meta keys.
     int m_modifierKeyState;
 };
 
 } // namespace WebCore
 
 #endif