GitLab

- Implements code to reject an incoming connection
- Adds checks in tests for data written to remote connection

Bug: 1085068
Change-Id: Ic8b1220b881b2adc20b0cd14793b38a1be50732e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2332707
Commit-Queue: Himanshu Jaju <himanshujaju@chromium.org>
Reviewed-by: Richard Knoll <knollr@chromium.org>
Cr-Commit-Position: refs/heads/master@{#795873}