We don't need these here, the testsuite is shipped with GTK.
This allows getting rid of popup windows.
Run the UI files through `gtk-builder-tool simplify --3to4` to update the layout properties.
The previous code for computing the clip rectangle forgot to respect the text-shadow CSS property. This is usually not very visible because text shadows usually don't extend the ink rectangle by very much. See attached testcase for an example.
