Add an abstract class for IceTransport

P2PTransportChannl will be renamed to IceTransport and this class will be
the base class of IceTransport. By doing this, the Dtls related methods
can be separated from the IceTransport.

For more detail, https://docs.google.com/document/d/1g9RA0s4RV7hFAcWiAM2b6H5ZohAVpBqcYienEDj6IcY/edit

BUG=none

Review-Url: https://codereview.webrtc.org/2577183004
Cr-Commit-Position: refs/heads/master@{#15690}

webrtc/p2p/BUILD.gn

@@ -29,6 +29,7 @@ rtc_static_library("rtc_p2p") {
     "base/common.h",
     "base/dtlstransportchannel.cc",
     "base/dtlstransportchannel.h",
+    "base/icetransportinternal.h",
     "base/jseptransport.cc",
     "base/jseptransport.h",
     "base/p2pconstants.cc",

webrtc/p2p/base/icetransportinternal.h

@@ -0,0 +1,131 @@
+/*
+ *  Copyright 2016 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_ICETRANSPORTINTERNAL_H_
+#define WEBRTC_P2P_BASE_ICETRANSPORTINTERNAL_H_
+
+#include <string>
+
+#include "webrtc/p2p/base/candidate.h"
+#include "webrtc/p2p/base/candidatepairinterface.h"
+#include "webrtc/p2p/base/jseptransport.h"
+#include "webrtc/p2p/base/packettransportinterface.h"
+#include "webrtc/p2p/base/transportdescription.h"
+
+namespace webrtc {
+class MetricsObserverInterface;
+}
+
+namespace cricket {
+
+enum class TransportState {
+  STATE_INIT,
+  STATE_CONNECTING,  // Will enter this state once a connection is created
+  STATE_COMPLETED,
+  STATE_FAILEDs
+};
+
+// TODO(zhihuang): Remove this once it's no longer used in
+// remoting/protocol/libjingle_transport_factory.cc
+enum IceProtocolType {
+  ICEPROTO_RFC5245  // Standard RFC 5245 version of ICE.
+};
+
+// IceTransportInternal is an internal abstract class that does ICE.
+// Once the public interface is supported,
+// (https://www.w3.org/TR/webrtc/#rtcicetransport-interface)
+// the IceTransportInterface will be split from this class.
+class IceTransportInternal : public rtc::PacketTransportInterface {
+ public:
+  virtual ~IceTransportInternal();
+
+  virtual TransportState GetState() const = 0;
+
+  virtual const std::string& transport_name() const = 0;
+
+  virtual int component() const = 0;
+
+  virtual IceRole GetIceRole() const = 0;
+
+  virtual void SetIceRole(IceRole role) = 0;
+
+  virtual void SetIceTiebreaker(uint64_t tiebreaker) = 0;
+
+  // TODO(zhihuang): Remove this once it's no longer called in
+  // remoting/protocol/libjingle_transport_factory.cc
+  virtual void SetIceProtocolType(IceProtocolType type) {}
+
+  virtual void SetIceCredentials(const std::string& ice_ufrag,
+                                 const std::string& ice_pwd) {
+    SetIceParameters(IceParameters(ice_ufrag, ice_pwd, false));
+  }
+
+  virtual void SetRemoteIceCredentials(const std::string& ice_ufrag,
+                                       const std::string& ice_pwd) {
+    SetRemoteIceParameters(IceParameters(ice_ufrag, ice_pwd, false));
+  }
+
+  // The ufrag and pwd in |ice_params| must be set
+  // before candidate gathering can start.
+  virtual void SetIceParameters(const IceParameters& ice_params) = 0;
+
+  virtual void SetRemoteIceParameters(const IceParameters& ice_params) = 0;
+
+  virtual void SetRemoteIceMode(IceMode mode) = 0;
+
+  virtual void SetIceConfig(const IceConfig& config) = 0;
+
+  // Start gathering candidates if not already started, or if an ICE restart
+  // occurred.
+  virtual void MaybeStartGathering() = 0;
+
+  virtual void SetMetricsObserver(
+      webrtc::MetricsObserverInterface* observer) = 0;
+
+  virtual void AddRemoteCandidate(const Candidate& candidate) = 0;
+
+  virtual void RemoveRemoteCandidate(const Candidate& candidate) = 0;
+
+  virtual IceGatheringState gathering_state() const = 0;
+
+  sigslot::signal1<IceTransportInternal*> SignalGatheringState;
+
+  // Handles sending and receiving of candidates.
+  sigslot::signal2<IceTransportInternal*, const Candidate&>
+      SignalCandidateGathered;
+
+  sigslot::signal2<IceTransportInternal*, const Candidates&>
+      SignalCandidatesRemoved;
+
+  // Deprecated by SignalSelectedCandidatePairChanged
+  // This signal occurs when there is a change in the way that packets are
+  // being routed, i.e. to a different remote location. The candidate
+  // indicates where and how we are currently sending media.
+  sigslot::signal2<IceTransportInternal*, const Candidate&> SignalRouteChange;
+
+  // Signalled when the current selected candidate pair has changed.
+  // The first parameter is the transport that signals the event.
+  // The second parameter is the new selected candidate pair. The third
+  // parameter is the last packet id sent on the previous candidate pair.
+  // The fourth parameter is a boolean which is true if the Transport
+  // is ready to send with this candidate pair.
+  sigslot::signal4<IceTransportInternal*, CandidatePairInterface*, int, bool>
+      SignalSelectedCandidatePairChanged;
+
+  // Invoked when the transport is being destroyed.
+  sigslot::signal1<IceTransportInternal*> SignalDestroyed;
+
+  // Debugging description of this transport.
+  std::string ToString() const;
+};
+
+}  // namespace cricket
+
+#endif  // WEBRTC_P2P_BASE_ICETRANSPORTINTERNAL_H_