Remove AsyncHttpRequest, AutoPortAllocator, ConnectivityChecker, and HttpPortAllocator.

BUG=webrtc:4149, webrtc:4456
R=deadbeef@webrtc.org, pbos@webrtc.org

Review URL: https://codereview.webrtc.org/1311353011 .

Cr-Commit-Position: refs/heads/master@{#9857}
14 files changed