Revert "TransportController refactoring."

This reverts commit 9af63f473e1d0d6c47a741a046c41642dfc1c178.

Cr-Original-Commit-Position: refs/heads/master@{#9994}
Cr-Mirrored-From: https://chromium.googlesource.com/external/webrtc
Cr-Mirrored-Commit: 8902433a43bbc9cc0de4966774d3dbbe37ef96fb
16 files changed