Add the URL attribute to cricket::Candiate. (Objc wrapper)

webrtc/sdk/objc/Framework/Classes/RTCIceCandidate.mm

Index: webrtc/sdk/objc/Framework/Classes/RTCIceCandidate.mm
diff --git a/webrtc/sdk/objc/Framework/Classes/RTCIceCandidate.mm b/webrtc/sdk/objc/Framework/Classes/RTCIceCandidate.mm
index 193403d11d8fcfd8157100c426128b64bb30e3f0..1d5b5f159403b99a425fba0e91cff7015f8895e7 100644
--- a/webrtc/sdk/objc/Framework/Classes/RTCIceCandidate.mm
+++ b/webrtc/sdk/objc/Framework/Classes/RTCIceCandidate.mm
@@ -20,24 +20,28 @@
 @synthesize sdpMid = _sdpMid;
 @synthesize sdpMLineIndex = _sdpMLineIndex;
 @synthesize sdp = _sdp;
+@synthesize serverUrl = _serverUrl;
 
 - (instancetype)initWithSdp:(NSString *)sdp
               sdpMLineIndex:(int)sdpMLineIndex
-                     sdpMid:(NSString *)sdpMid {
+                     sdpMid:(NSString *)sdpMid
+                  serverUrl:(NSString *)serverUrl {
   NSParameterAssert(sdp.length);
   if (self = [super init]) {
     _sdpMid = [sdpMid copy];
     _sdpMLineIndex = sdpMLineIndex;
     _sdp = [sdp copy];
+    _serverUrl = [serverUrl copy];
   }
   return self;
 }
 
 - (NSString *)description {
-  return [NSString stringWithFormat:@"RTCIceCandidate:\n%@\n%d\n%@",
+  return [NSString stringWithFormat:@"RTCIceCandidate:\n%@\n%d\n%@\n%@",
                                     _sdpMid,
                                     _sdpMLineIndex,
-                                    _sdp];
+                                    _sdp,
+                                    _serverUrl];
 }
 
 #pragma mark - Private
@@ -50,7 +54,8 @@
 
   return [self initWithSdp:[NSString stringForStdString:sdp]
              sdpMLineIndex:candidate->sdp_mline_index()
-                    sdpMid:[NSString stringForStdString:candidate->sdp_mid()]];
+                    sdpMid:[NSString stringForStdString:candidate->sdp_mid()]
+                 serverUrl:[NSString stringForStdString:candidate->server_url()]];
 }
 
 - (std::unique_ptr<webrtc::IceCandidateInterface>)nativeCandidate {