aFilter is useful for determining if a frame should output itself during
a List(). In any event, the children of the frame are always processed.
added nsIListFilter, an interface for any object that wants to act like a filter for frame dumps
added static NS_LAYOUT nsIListFilter * GetFilter(nsString *aFilterName);
currently, only TableListFilter implements nsIListFilter.
in response to List(...TableListFilter), the frame model is dumped in a way that is useful
for table layout regression testing. Currently this is controlled by command line switches on the viewer app.
git-svn-id: svn://10.0.0.236/trunk@9156 18797224-902f-48f8-a5cc-f745e15eee43