nsGfxScrollFrameInner::LayoutScrollbars should be setting the vertical scrollbar width to zero or the horizontal height to zero when we don't want that scrollbar to be visible. Stepping through that function when we're reflowing the scroll area of interest would be interesting.
nsGfxScrollFram eInner: :LayoutScrollba rs should be setting the vertical scrollbar width to zero or the horizontal height to zero when we don't want that scrollbar to be visible. Stepping through that function when we're reflowing the scroll area of interest would be interesting.