updated to new multiple-item d&d apis.

widget/src/gtk/nsDragService.cpp

@@ -87,7 +87,8 @@ NS_IMETHODIMP nsDragService::StartDragSession (nsITransferable * aTransferable,
 }
 
 //-------------------------------------------------------------------------
-NS_IMETHODIMP nsDragService::GetData (nsITransferable * aTransferable)
+NS_IMETHODIMP nsDragService::GetData (nsITransferable * aTransferable,
+                                        PRUint32 aItemIndex)
 {
   return NS_ERROR_FAILURE;
 }

widget/src/gtk/nsDragService.h

@@ -43,7 +43,7 @@ public:
                                PRUint32 aActionType);
 
   // Native Impl.
-  NS_IMETHOD GetData (nsITransferable * aTransferable);
+  NS_IMETHOD GetData (nsITransferable * aTransferable, PRUint32 aItemIndex);
 
   static void SetTopLevelWidget(GtkWidget* w);