Remove unused 4-argument version of OnIceCandidateError.

It has not been used since
https://chromium-review.googlesource.com/c/chromium/src/+/1944346.

Bug: webrtc:13446
Change-Id: Ice9c418435bc7958562eb73524d7651a79508ab6
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/241440
Reviewed-by: Harald Alvestrand <hta@webrtc.org>
Reviewed-by: Henrik Boström <hbos@webrtc.org>
Commit-Queue: Henrik Boström <hbos@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#35541}
diff --git a/api/peer_connection_interface.h b/api/peer_connection_interface.h
index 6d42b84..7a2ac12 100644
--- a/api/peer_connection_interface.h
+++ b/api/peer_connection_interface.h
@@ -1297,14 +1297,6 @@
 
   // Gathering of an ICE candidate failed.
   // See https://w3c.github.io/webrtc-pc/#event-icecandidateerror
-  // `host_candidate` is a stringified socket address.
-  virtual void OnIceCandidateError(const std::string& host_candidate,
-                                   const std::string& url,
-                                   int error_code,
-                                   const std::string& error_text) {}
-
-  // Gathering of an ICE candidate failed.
-  // See https://w3c.github.io/webrtc-pc/#event-icecandidateerror
   virtual void OnIceCandidateError(const std::string& address,
                                    int port,
                                    const std::string& url,
diff --git a/pc/peer_connection.cc b/pc/peer_connection.cc
index 885f557..94a00d2 100644
--- a/pc/peer_connection.cc
+++ b/pc/peer_connection.cc
@@ -1938,8 +1938,6 @@
     return;
   }
   Observer()->OnIceCandidateError(address, port, url, error_code, error_text);
-  // Leftover not to break wpt test during migration to the new API.
-  Observer()->OnIceCandidateError(address + ":", url, error_code, error_text);
 }
 
 void PeerConnection::OnIceCandidatesRemoved(