Revert of Remove GetTransport() from TransportChannelImpl

webrtc/p2p/quic/quicsession_unittest.cc

Index: webrtc/p2p/quic/quicsession_unittest.cc
diff --git a/webrtc/p2p/quic/quicsession_unittest.cc b/webrtc/p2p/quic/quicsession_unittest.cc
index 765a47f0c217306d5e81f618b729cf8ef79587a3..67337961276e7df7dd04f05d456ca6f3f92465b4 100644
--- a/webrtc/p2p/quic/quicsession_unittest.cc
+++ b/webrtc/p2p/quic/quicsession_unittest.cc
@@ -286,9 +286,9 @@
 // establishes encryption with client.
 void QuicSessionTest::CreateClientAndServerSessions() {
   scoped_ptr<FakeTransportChannel> channel1(
-      new FakeTransportChannel("channel1", 0));
+      new FakeTransportChannel(nullptr, "channel1", 0));
   scoped_ptr<FakeTransportChannel> channel2(
-      new FakeTransportChannel("channel2", 0));
+      new FakeTransportChannel(nullptr, "channel2", 0));
 
   // Prevent channel1->OnReadPacket and channel2->OnReadPacket from calling
   // themselves in a loop, which causes to future packets to be recursively