Add basic ServiceConnection unit test

The is just testing that ServiceConnection::BindModelProvider returns
successfully. The Mojo invitation won't go anywhere beyond the no-op
FakeMachineLearningClient D-Bus client.

To make this test compile, I had to fix an #include from an
overlooked file rename in an earlier CL ...

Bug: 863794

Change-Id: Ifd31fea950145561cd5954ae16e930b801bfe49b
Reviewed-on: https://chromium-review.googlesource.com/1139942
Commit-Queue: Andrew Moylan <amoylan@chromium.org>
Reviewed-by: Ken Rockot <rockot@chromium.org>
Reviewed-by: Dan Erat <derat@chromium.org>
Cr-Commit-Position: refs/heads/master@{#578329}
7 files changed