Revert of "Remove the obsolete enum webrtc::PeerConnectionInterface::IceState."

webrtc/api/peerconnection.h

Index: webrtc/api/peerconnection.h
diff --git a/webrtc/api/peerconnection.h b/webrtc/api/peerconnection.h
index 84ff100a0d7f48140bb2d4953ff0e5963e200ea2..3087160e4329aad293f4ce272d7b5b426f5b17ff 100644
--- a/webrtc/api/peerconnection.h
+++ b/webrtc/api/peerconnection.h
@@ -107,6 +107,8 @@
 
   SignalingState signaling_state() override;
 
+  // TODO(bemasc): Remove ice_state() when callers are removed.
+  IceState ice_state() override;
   IceConnectionState ice_connection_state() override;
   IceGatheringState ice_gathering_state() override;
 
@@ -384,6 +386,8 @@
   PeerConnectionObserver* observer_;
   UMAObserver* uma_observer_;
   SignalingState signaling_state_;
+  // TODO(bemasc): Remove ice_state_.
+  IceState ice_state_;
   IceConnectionState ice_connection_state_;
   IceGatheringState ice_gathering_state_;