Revert of Remove GetTransport() from TransportChannelImpl

webrtc/p2p/base/p2ptransportchannel.h

Index: webrtc/p2p/base/p2ptransportchannel.h
diff --git a/webrtc/p2p/base/p2ptransportchannel.h b/webrtc/p2p/base/p2ptransportchannel.h
index c49f48b3447497fb5850d9de83f0deeb7fcce2a7..f2e93153432be261dc72083eb5a1ad948397d546 100644
--- a/webrtc/p2p/base/p2ptransportchannel.h
+++ b/webrtc/p2p/base/p2ptransportchannel.h
@@ -27,6 +27,7 @@
 #include "webrtc/p2p/base/p2ptransport.h"
 #include "webrtc/p2p/base/portallocator.h"
 #include "webrtc/p2p/base/portinterface.h"
+#include "webrtc/p2p/base/transport.h"
 #include "webrtc/p2p/base/transportchannelimpl.h"
 #include "webrtc/base/asyncpacketsocket.h"
 #include "webrtc/base/sigslot.h"
@@ -66,10 +67,12 @@
  public:
   P2PTransportChannel(const std::string& transport_name,
                       int component,
+                      P2PTransport* transport,
                       PortAllocator* allocator);
   virtual ~P2PTransportChannel();
 
   // From TransportChannelImpl:
+  Transport* GetTransport() override { return transport_; }
   TransportChannelState GetState() const override;
   void SetIceRole(IceRole role) override;
   IceRole GetIceRole() const override { return ice_role_; }
@@ -261,6 +264,7 @@
                : static_cast<uint32_t>(remote_ice_parameters_.size() - 1);
   }
 
+  P2PTransport* transport_;
   PortAllocator* allocator_;
   rtc::Thread* worker_thread_;
   bool incoming_only_;