[PresentationService] Improve PresentationServiceImplTest.
- Remove PresentationServicePtr - the unit tests should just invoke
the PresentationServiceImpl directly for simplicity. This also allows
us to remove the usage of RunLoop::QuitClosure and RunLoop::Run and
replace with RunLoop::RunUntilIdle.
- Remove a bunch of FRIEND_CLASS_TEST_PREFIX and move the Mojo
PresentationService overrides to public.
- Remove other unused functions in the test.
BUG=699225
Review-Url: https://codereview.chromium.org/2938023002
Cr-Commit-Position: refs/heads/master@{#479748}
2 files changed
