Remove ScopedTaskEnvironment references from search_suggest_service_unittest.cc

This is follow up implementation for CL1414740. Removed call to
RunUntilIdle as SetCookieAccounts internally run loop

Bug: 921611
Change-Id: I5431c9b1665f6aa84a0beb3be7ea88c012e21d7c
Reviewed-on: https://chromium-review.googlesource.com/c/1417432
Commit-Queue: Abhijeet Kandalkar <abhijeet@igalia.com>
Reviewed-by: Colin Blundell <blundell@chromium.org>
Reviewed-by: Kyle Milka <kmilka@chromium.org>
Reviewed-by: Antonio Gomes <tonikitoo@igalia.com>
Cr-Commit-Position: refs/heads/master@{#624458}
1 file changed