Comment 1 for bug 1661521

Bisected (on lp:mir). The failure started in:

------------------------------------------------------------
revno: 4000 [merge]
author: Kevin DuBois <email address hidden>
committer: Tarmac
branch nick: development-branch
timestamp: Mon 2017-01-30 06:37:42 +0000
message:
  mirbuffer: remove MirBufferUsage from buffer allocation. mir_connection_alloca
te_buffer will allocate the formerly-called "software buffer", and there are pla
tform-specific extensions for android and mesa, which allocate the formerly-call
ed 'hardware buffers'.

  Approved by mir-ci-bot, Chris Halse Rogers, Cemil Azizoglu, Alan Griffiths.
------------------------------------------------------------