aRect is always in pixels

Change-Id: Ib122a2f970a7852e2979a5301f635f9f1a4ce87b
Reviewed-on: https://gerrit.libreoffice.org/70214
Tested-by: Jenkins
Reviewed-by: Caolán McNamara <caolanm@redhat.com>
Tested-by: Caolán McNamara <caolanm@redhat.com>

vcl/unx/gtk3/gtk3gtkinst.cxx

@@ -7500,7 +7500,7 @@ private:
         if (!gdk_cairo_get_clip_rectangle(cr, &rect))
             return;
         tools::Rectangle aRect(Point(rect.x, rect.y), Size(rect.width, rect.height));
-        m_xDevice->Erase(aRect);
+        m_xDevice->Erase(m_xDevice->PixelToLogic(aRect));
         m_aDrawHdl.Call(std::pair<vcl::RenderContext&, const tools::Rectangle&>(*m_xDevice, aRect));
         cairo_surface_mark_dirty(m_pSurface);