[gtk] (3 commits) Non-fast-forward update to branch wip/otte/display-gl

[Benjamin Otte <otte src gnome org>]

The branch 'wip/otte/display-gl' 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:

  a915283... gsk: Allow gsk_renderer_realize (renderer, NULL, NULL)
  ff57fdb... node-editor: Create renderers surfaceless
  272950c... testsuite: Create GL renderers without surfaces

Commits added to the branch:

  cb03fe8... gsk: Allow gsk_renderer_realize (renderer, NULL, NULL)
  869d2f2... node-editor: Create renderers surfaceless
  0898023... testsuite: Create GL renderers without surfaces