Fixing SignalSentPacket for TCP connections.

The signal was only being hooked up for incoming connections, not
outgoing connections.

As a result, the bandwidth estimator didn't know when packets were sent
and couldn't calculate delays.

BUG=webrtc:7509

Review-Url: https://codereview.webrtc.org/2834083002
Cr-Original-Commit-Position: refs/heads/master@{#17817}
Cr-Mirrored-From: https://chromium.googlesource.com/external/webrtc
Cr-Mirrored-Commit: 06878297942a3d632dce62df18b2fe0c32cbd853
2 files changed