[gtk] (6 commits) Non-fast-forward update to branch wip/matthiasc/gsk-hdr

[Matthias Clasen <matthiasc src gnome org>]

The branch 'wip/matthiasc/gsk-hdr' 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:

  cabaee1... texture: Add high depth api
  d6f407d... gsk: Add high depth rendernode api
  76c011e... ngl: Allow specifying texture formats
  dc8b395... ngl: Determine intermediate formats
  1facecd... ngl: Update framebuffer format for each frame
  6141122... ngl: Make render_texture high depth aware

Commits added to the branch:

  8950c0d... texture: Make format a property of GdkTexture (*)
  7201a30... gsk: Add high depth rendernode api
  f11bafc... ngl: Allow specifying texture formats
  6dc5065... ngl: Determine intermediate formats
  2a29b5c... ngl: Update framebuffer format for each frame
  ba95b0d... ngl: Make render_texture high depth aware

(*) This commit already existed in another branch; no separate mail sent