GitLab

Use the TestBrowserThreadBundle RunUntilIdle to flush all tasks at the
end of the test, rather than base::Runloop::RunUntilIdle, which caused
flakes on the MSAN/ASAN bots.

Test: unit_tests --gtest_filter=FileManagerFileWatcher*WatchLocalFile
Bug: 813483
Change-Id: I867e5d914074e6c9d389a5f932836cd6cd8a627c
Reviewed-on: https://chromium-review.googlesource.com/1113399Reviewed-by: Stuart Langley <slangley@chromium.org>
Commit-Queue: Noel Gordon <noel@chromium.org>
Cr-Commit-Position: refs/heads/master@{#570264}