node.cloneNode() should clone the value of file upload elements

Source/core/html/forms/InputType.h

Index: Source/core/html/forms/InputType.h
diff --git a/Source/core/html/forms/InputType.h b/Source/core/html/forms/InputType.h
index 20f415a8329aebd92d56ee858e402ad4c3361353..722e6c7576ac629620d61b2724c03defb9b73b8b 100644
--- a/Source/core/html/forms/InputType.h
+++ b/Source/core/html/forms/InputType.h
@@ -172,6 +172,7 @@ public:
     // Should return true if the given DragData has more than one dropped files.
     virtual bool receiveDroppedFiles(const DragData*);
     virtual String droppedFileSystemId();
+    virtual void copyFiles(PassRefPtrWillBeRawPtr<FileList>);
     // Should return true if the corresponding renderer for a type can display a suggested value.
     virtual bool canSetSuggestedValue();
     virtual bool shouldSendChangeEventAfterCheckedChanged();