With csd, the allocation of the window will be larger than the default size, since it includes borders and decorations. Just remove this check.
Skip tests that don't work under Wayland, such as tests for GtkPlug and GtkSocket.
This commit adds a test that checks whether or not hide-titlebar-when-maximized can be set before the window is realized. https://bugzilla.gnome.org/show_bug.cgi?id=740287
