GitLab

When shutting down HostProcess config_watcher_ is supposed to be deleted
on the nework thread. Previously ShutdownOnNetworkThread() was deleting
it, but that line was mistakenly removed in crrev.com/302162 . Adding
it back.

Review URL: https://codereview.chromium.org/885693003

Cr-Commit-Position: refs/heads/master@{#313623}