[mutter] (2 commits) Non-fast-forward update to branch wip/carlosg/empty-invalidations

[Carlos Garnacho <carlosg 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:

  6f84ca5... clutter/cogl: Store empty clip regions for buffer age
  075835e... clutter/cogl: Ensure to paint full view if there's no buffe

Commits added to the branch:

  3673660... clutter/cogl: Store empty clip regions for buffer age
  c499826... clutter/cogl: Ensure to paint full view if there's no buffe