Revert of Refactoring that removes P2PTransport and DtlsTransport classes.

webrtc/p2p/base/p2ptransport.h

+/*
+ *  Copyright 2004 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef WEBRTC_P2P_BASE_P2PTRANSPORT_H_
+#define WEBRTC_P2P_BASE_P2PTRANSPORT_H_
+
+#include <string>
+
+#include "webrtc/base/constructormagic.h"
+#include "webrtc/p2p/base/transport.h"
+
+namespace cricket {
+
+// Everything in this class should be called on the network thread.
+class P2PTransport : public Transport {
+ public:
+  P2PTransport(const std::string& name, PortAllocator* allocator);
+  virtual ~P2PTransport();
+
+ protected:
+  // Creates and destroys P2PTransportChannel.
+  virtual TransportChannelImpl* CreateTransportChannel(int component);
+  virtual void DestroyTransportChannel(TransportChannelImpl* channel);
+
+  friend class P2PTransportChannel;
+
+  RTC_DISALLOW_COPY_AND_ASSIGN(P2PTransport);
+};
+
+}  // namespace cricket
+
+#endif  // WEBRTC_P2P_BASE_P2PTRANSPORT_H_