The Clutter backend split is opaque enough that should allow us to just
build all possible backends inside the same shared object, and select
the wanted backend at initialization time.
This requires some work in the build system, as well as the
initialization code, to remove duplicate functions that might cause
conflicts at build and link time. We also need to defer all the checks
of the internal state of the platform-specific API to run-time type
checks.
This adds a performance tracking framework that can run a set of tests over
specified git revisions. The ruby script for generating the reports comes from
similar performance tracking in GEGL. The framework permits evaluating new
tests against older version of clutter.
The tests themselves go through a few hoops for disabling framerate limiting in
both mesa and clutter.
When running make check the tests will be run and lines of the form:
@ test-state: 40.51 fps
will be left in the output, a script can scrape these lines out of a build log
on a buildbot to in other ways track performance.
