setData() of DataTransfer has a void return type

Source/core/clipboard/DataObject.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 57 matching lines @@
     void clearAll();
     // Returns null if an item already exists with the provided type.
     PassRefPtrWillBeRawPtr<DataObjectItem> add(const String& data, const String& type);
     PassRefPtrWillBeRawPtr<DataObjectItem> add(PassRefPtrWillBeRawPtr<File>);
 
     // WebCore helpers.
     void clearData(const String& type);
 
     ListHashSet<String> types() const;
     String getData(const String& type) const;
-    bool setData(const String& type, const String& data);
+    void setData(const String& type, const String& data);
 
     void urlAndTitle(String& url, String* title = 0) const;
     void setURLAndTitle(const String& url, const String& title);
     void htmlAndBaseURL(String& html, KURL& baseURL) const;
     void setHTMLAndBaseURL(const String& html, const KURL& baseURL);
 
     // Used for dragging in files from the desktop.
     bool containsFilenames() const;
     Vector<String> filenames() const;
     void addFilename(const String& filename, const String& displayName);
@@ skipping 21 matching lines @@
     WillBeHeapVector<RefPtrWillBeMember<DataObjectItem> > m_itemList;
 
     // State of Shift/Ctrl/Alt/Meta keys.
     int m_modifierKeyState;
     String m_filesystemId;
 };
 
 } // namespace WebCore
 
 #endif