Revert of make the DtlsTransportWrapper inherit form DtlsTransportInternal

webrtc/p2p/base/jseptransport.h

Index: webrtc/p2p/base/jseptransport.h
diff --git a/webrtc/p2p/base/jseptransport.h b/webrtc/p2p/base/jseptransport.h
index c7998ba0fb46aca846bced52544916a038a17cb5..dcf4a5f6d1a92346490609bb185d76c8085499f0 100644
--- a/webrtc/p2p/base/jseptransport.h
+++ b/webrtc/p2p/base/jseptransport.h
@@ -29,7 +29,8 @@
 
 namespace cricket {
 
-class DtlsTransportInternal;
+class TransportChannelImpl;
+class TransportChannelImpl;
 enum class IceCandidatePairState;
 
 typedef std::vector<Candidate> Candidates;
@@ -246,7 +247,7 @@
   // Add or remove channel that is affected when a local/remote transport
   // description is set on this transport. Need to add all channels before
   // setting a transport description.
-  bool AddChannel(DtlsTransportInternal* dtls, int component);
+  bool AddChannel(TransportChannelImpl* dtls, int component);
   bool RemoveChannel(int component);
   bool HasChannels() const;
 
@@ -332,18 +333,17 @@
 
   // Pushes down the transport parameters from the local description, such
   // as the ICE ufrag and pwd.
-  bool ApplyLocalTransportDescription(DtlsTransportInternal* dtls_transport,
+  bool ApplyLocalTransportDescription(TransportChannelImpl* channel,
                                       std::string* error_desc);
 
   // Pushes down the transport parameters from the remote description to the
   // transport channel.
-  bool ApplyRemoteTransportDescription(DtlsTransportInternal* dtls_transport,
+  bool ApplyRemoteTransportDescription(TransportChannelImpl* channel,
                                        std::string* error_desc);
 
   // Pushes down the transport parameters obtained via negotiation.
-  bool ApplyNegotiatedTransportDescription(
-      DtlsTransportInternal* dtls_transport,
-      std::string* error_desc);
+  bool ApplyNegotiatedTransportDescription(TransportChannelImpl* channel,
+                                           std::string* error_desc);
 
   const std::string mid_;
   // needs-ice-restart bit as described in JSEP.
@@ -357,7 +357,7 @@
   bool remote_description_set_ = false;
 
   // Candidate component => DTLS channel
-  std::map<int, DtlsTransportInternal*> channels_;
+  std::map<int, TransportChannelImpl*> channels_;
 
   RTC_DISALLOW_COPY_AND_ASSIGN(JsepTransport);
 };