[gtk] (19 commits) ...Merge branch 'wip/baedert/radial-gradient' into 'master'

[Matthias Clasen <matthiasc src gnome org>]

Summary of changes:

  0c6226c... gsk: Add a radial gradient node (*)
  66d1604... snapshot: Add api for radial gradients (*)
  2881d34... css: Use snapshot api for radial gradients (*)
  ebfb3e7... rendernode: switch to h/vradius (*)
  c08df82... snapshot: switch to h/vradius (*)
  2886e19... css: switch to h/vradius (*)
  6a08981... gsk: Parse radial gradient nodes (*)
  dbfc172... radial gradients: Allow 0 start/end values (*)
  0c2d008... gl renderer: Set an error if we don't have one already (*)
  07b6431... Inspector: Show radial gradient node info (*)
  2c5a4a7... rendernode: Pull local variable into closest scope (*)
  b8e4240... gl renderer: Add radial gradient shader (*)
  a770ab3... gl renderer: Consolidate color pre-multiplication (*)
  5d5fbc6... rendernodes: Enfore end > start for radial gradient nodes (*)
  6e14b26... gsk: Add docs for radial gradient nodes (*)
  f938377... rendernodes: Clarify color_stops arguments (*)
  1d371db... scrolledwindow: Ignore captured motion events if no child i (*)
  79dc25e... cssimageradial: Avoid creating color stops with an offset > (*)
  57253b0... Merge branch 'wip/baedert/radial-gradient' into 'master'

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