[mutter] (15 commits) Non-fast-forward update to branch wip/carlosg/empty-invalidations

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

The branch 'wip/carlosg/empty-invalidations' 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:

  71860d3... clutter/cogl: Store empty clip regions for buffer age
  fdbd4c2... clutter/cogl: Ensure to paint full view if there's no buffe

Commits added to the branch:

  ac626f7... cogl: Remove unused API from cogl-xlib (*)
  b3980f7... cogl: Move _cogl_xlib_get_damage_base near its only consume (*)
  95662fd... cogl: Remove unused cogl_xlib_renderer_get_visual_info (*)
  acc7b83... cogl: Remove the stub winsys (*)
  a99f579... cogl: Remove unused cogl_check_extension and cogl_clutter_c (*)
  c36c865... cogl: Remove unused _cogl_xlib_renderer_get_dispatch_timeou (*)
  e17494f... cogl: Inline cogl_xlib_renderer_set_event_retrieval_enabled (*)
  683f186... cogl: Remove unused cogl_x11_onscreen_get_visual_xid (*)
  ed7afd9... cogl: Remove unused cogl_x11_onscreen_set_foreign_window_xi (*)
  3186e45... cogl: Remove unused cogl_xlib_renderer_get_visual_info (*)
  c63f54b... cogl: Remove unused cogl_texture_pixmap_x11_set_damage_obje (*)
  b294e62... cogl: Remove unused cogl_glx_context_get_glx_context (*)
  3e5960b... cogl: Remove unused cogl_egl_context_get_egl_context (*)
  4918893... clutter/cogl: Store empty clip regions for buffer age
  2e9faaf... clutter/cogl: Ensure to paint full view if there's no buffe

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