Fix the failed test on Mac for subdomain partitioner interface

[fdkong]

There was a mistake when rebased the code by taking head changes. We need to add subdomain_partitioner into MooseEnum .

Refs #8672

[moosebuild]

Job Precheck:linux-gnu on 38e1d2f wanted to post the following:

Your code requires style changes.
In the top level of your repository, you can run:

git clang-format 583badf8b5e51d7acd3e1f12eed2b76dc4b1dbff

Alternatively, apply the patch found here.
You can directly apply the patch by running:

curl -s http://mooseframework.org/docs/PRs/8950/style.patch | git apply -v

[jwpeterson]

There was a mistake when rebased the code by taking head changes.

I still don't see how this passed all the testing on devel and master.

[jwpeterson]

I still don't see how this passed all the testing on devel and master.

Oh I see now, the test is restricted to Mac because of architecture-dependent partitioning differences...

[fdkong]

I am going to add a linux test as well.

[permcody]

#8948 will repair the broken test you are currently seeing on the Mac side.

[permcody]

Failed test is unrelated to the PR.