[mutter] (16 commits) Non-fast-forward update to branch gbsneto/content

[Georges Basile Stavracas Neto <gbsneto src gnome org>]

The branch 'gbsneto/content' 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:

  f63bfc8... clutter/paint-node: Expose clutter_paint_node_get_framebuff
  dc4fffe... shaped-texture: Implement ClutterContent
  a4a7e48... wayland/actor-surface: Set geometry scale in surface actor
  e871550... shaped-texture: Draw pipeline relative to alloc
  86e840a... shaped-texture: Move MetaCullable helpers to MetaSurfaceAct
  a120f7f... shaped-texture: Move private function to private header
  e1eb0c3... wayland/tablet-tool: Use meta_wayland_surface_get_relative_
  d40a10a... wayland: Don't scale input and opaque regions
  4c1768d... window-actor: Handle geometry scale

Commits added to the branch:

  2812338... shadow-factory: Optimize shadows entirely if clip region is (*)
  0f6ab78... window-actor: Check frame bounds region before use (*)
  cc59681... window-actor: Fix check to clip beneath the window (*)
  ac7aa11... window-actor: Cull out areas covered by opaque windows (*)
  90a5582... background-actor: Clip obscured background areas (*)
  f501fdc... window-actor: Remove negation in function name (*)
  aae9f3a... window-actor: Fix rectangle coordinates in culling (*)
  9f5dc29... clutter/paint-node: Expose clutter_paint_node_get_framebuff
  2baa0f4... shaped-texture: Implement ClutterContent
  631f049... wayland/actor-surface: Set geometry scale in surface actor
  22b36a2... shaped-texture: Draw pipeline relative to alloc
  3edd19d... shaped-texture: Move MetaCullable helpers to MetaSurfaceAct
  0e67ca9... shaped-texture: Move private function to private header
  538bf43... wayland/tablet-tool: Use meta_wayland_surface_get_relative_
  067c5cb... wayland: Don't scale input and opaque regions
  4bf41e3... window-actor: Handle geometry scale

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