[gtk] Non-fast-forward update to branch wip/baedert/gl-rework

[Timm Bäder <baedert src gnome org>]

The branch 'wip/baedert/gl-rework' was changed in a way that was not a fast-forward update.
NOTE: This may cause problems for people pulling from the branch. For more information,
please see:

 https://wiki.gnome.org/Git/Help/NonFastForward

Commits removed from the branch:

  2b669ce... cssimageicontheme: Implement is_computed
  a0ee532... cssimagepaintable: Implement is_computed()
  1a010b2... cssimage: Skip is_computed images
  2faa44e... cssimage: Remove _gtk_css_image_draw
  347395d... Revert "cssimageicontheme: Implement is_computed"

Commits added to the branch:

  3027dfd... cssimagepaintable: Implement is_computed()