GitLab

This will allow NetBenchmarking to be used with the network service
enabled. This also adds a NetworkContext::CloseAllConnections method.

Bug: 824974
Cq-Include-Trybots: luci.chromium.try:linux_mojo
Change-Id: I566124d13e6607d579583202f030425ec2f3c598
Reviewed-on: https://chromium-review.googlesource.com/1135715Reviewed-by: Daniel Cheng <dcheng@chromium.org>
Reviewed-by: John Abd-El-Malek <jam@chromium.org>
Reviewed-by: Matt Menke <mmenke@chromium.org>
Commit-Queue: Robbie McElrath <rmcelrath@chromium.org>
Cr-Commit-Position: refs/heads/master@{#577642}