Do not post tasks with random delays in AfterStartupTaskUtils for browser tests.

This removes non-determinism and makes tests run more reliably.

BUG=905266

Change-Id: I1350e5aa9d1c5571c2fd763f226c8282b8e5f955
Reviewed-on: https://chromium-review.googlesource.com/c/1405725
Reviewed-by: Henrik Grunell <grunell@chromium.org>
Reviewed-by: Eric Seckler <eseckler@chromium.org>
Reviewed-by: Gabriel Charette <gab@chromium.org>
Commit-Queue: Lei Zhang <thestig@chromium.org>
Cr-Commit-Position: refs/heads/master@{#622090}
3 files changed