Fixes https://github.com/electron/electron/issues/45990
We previously made a change in https://github.com/electron/electron/pull/45868
to fix content protection being lost on hide and re-show. However, this
cause a breaking change where protected windows were made opaque black
instead of being hidden as before. This overrides relevant methods in
ElectronDesktopWindowTreeHostWin to restore the previous behavior.
without regressing the original issue.