File selectors may have been added in QQuickStylePlugin::registerTypes(). It makes sense to clean them up when a style plugin in unloaded, otherwise the first style that was loaded will always be prioritized, even if it was unloaded later on, during runtime. This change causes tst_qquickfiledialogimpl to acutally run with all styles (except Imagine). Originally I thought da777a75f65ad101e9b0bad7c098004c0a699b41 would work by itself, but it turns out that the test would run 4 times with the same style (Basic), instead of the intended Basic, Fusion, Material and Universal styles. By cleaning up old selectors, the test will now finally run will all the different styles. This caused some of the test functions to break. The Material style is infamous for having transitions for opening and closing popups. There were a few other functions too that broke for other reasons. Fixes for those functions are also included in this patch. Change-Id: I3c350b5e72454fccedbc2579db4813d953dfbb95 Reviewed-by: Mitch Curtis <mitch.curtis@qt.io>