[gtk] (7 commits) Non-fast-forward update to branch wip/baedert/for-master

[Timm Bäder <baedert src gnome org>]

The branch 'wip/baedert/for-master' 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:

  f360b47... cssvalue: Make some functions pure
  d2ed49c... cssimage: Make some function pure
  0107327... GdkRGBA: Make snome functions pure
  9702d1b... gsk: Make a few functions G_GNUC_PURE
  1c215a7... csscolorvalue: Make some functions pure
  53fa807... GdkTexture: Make get_width/get_height pure
  786015d... GtkCssImageUrl: Implement is_computed()
  3094fb9... cssprovider: Parse selectors without a GList
  51aec2f... cssparser: make a few local variables const
  bfe3583... css: Make a few token functions pure
  e05b48a... Remove gtkutils{.c,private.h}
  4772c3d... css: Some more pure/const annotations

Commits added to the branch:

  f0274e3... GtkCssImageUrl: Implement is_computed()
  929dd6a... cssprovider: Parse selectors without a GList
  56d0d45... cssparser: make a few local variables const
  e07d1fd... Remove gtkutils{.c,private.h}
  a06dea1... render: Remove gtk_render_background_get_clip
  bdc849a... Add pure and const annotations to various functions
  b7485d0... renderbackground: Avoid unnecessary work in snapshot_backgr