Refactor sequence_manager_impl_unittest.cc

Migrate MessagePump tests to common interface.

SequenceManager on top of ThreadControllerWithMessagePump does not
support deletion from a task. Add a check in the code and perform the
delete from task test only for ThreadControllerImpl

Bug: 891670
Change-Id: I27a23a2bf53ec0dd9c59b2ce88de39d2be8b50d1
Reviewed-on: https://chromium-review.googlesource.com/c/1451904
Reviewed-by: Alex Clarke <alexclarke@chromium.org>
Reviewed-by: Sami Kyöstilä <skyostil@chromium.org>
Reviewed-by: Alexander Timin <altimin@chromium.org>
Commit-Queue: Carlos Caballero <carlscab@google.com>
Cr-Commit-Position: refs/heads/master@{#629617}
2 files changed