Remove the dependency of TransportChannel and TransportChannelImpl.

webrtc/p2p/base/dtlstransportchannel_unittest.cc

Index: webrtc/p2p/base/dtlstransportchannel_unittest.cc
diff --git a/webrtc/p2p/base/dtlstransportchannel_unittest.cc b/webrtc/p2p/base/dtlstransportchannel_unittest.cc
index 3efc1e7df9fddf23130d94be7a3ba363014bebe0..a800fc57e514acc8504b380aa83470204afa0d13 100644
--- a/webrtc/p2p/base/dtlstransportchannel_unittest.cc
+++ b/webrtc/p2p/base/dtlstransportchannel_unittest.cc
@@ -99,8 +99,9 @@ class DtlsTestClient : public sigslot::has_slots<> {
       cricket::DtlsTransportChannelWrapper* channel =
           new cricket::DtlsTransportChannelWrapper(fake_ice_channel);
       channel->SetLocalCertificate(certificate_);
-      channel->SetIceRole(role);
-      channel->SetIceTiebreaker((role == cricket::ICEROLE_CONTROLLING) ? 1 : 2);
+      channel->ice_transport()->SetIceRole(role);
+      channel->ice_transport()->SetIceTiebreaker(
+          (role == cricket::ICEROLE_CONTROLLING) ? 1 : 2);
       channel->SetSslMaxProtocolVersion(ssl_max_version_);
       channel->SignalWritableState.connect(this,
         &DtlsTestClient::OnTransportChannelWritableState);
@@ -236,7 +237,7 @@ class DtlsTestClient : public sigslot::has_slots<> {
       return false;
     }
     for (const auto& channel : channels_) {
-      if (!channel->channel()->writable()) {
+      if (!channel->ice_transport()->writable()) {
         return false;
       }
     }