Update ice server provider response format in iOS AppRTCMobile

webrtc/examples/objc/AppRTCMobile/ARDAppClient.m

Index: webrtc/examples/objc/AppRTCMobile/ARDAppClient.m
diff --git a/webrtc/examples/objc/AppRTCMobile/ARDAppClient.m b/webrtc/examples/objc/AppRTCMobile/ARDAppClient.m
index 40a2be7cbf8cc3ec5d2c96f10d7693ba2504dcd7..ef21ab617b7efdc279a465b0a477de4d3e8fd12e 100644
--- a/webrtc/examples/objc/AppRTCMobile/ARDAppClient.m
+++ b/webrtc/examples/objc/AppRTCMobile/ARDAppClient.m
@@ -23,7 +23,7 @@
 #import "WebRTC/RTCTracing.h"
 
 #import "ARDAppEngineClient.h"
-#import "ARDCEODTURNClient.h"
+#import "ARDTURNClient+Internal.h"
 #import "ARDJoinResponse.h"
 #import "ARDMessageResponse.h"
 #import "ARDSDPUtils.h"
@@ -33,12 +33,7 @@
 #import "RTCIceCandidate+JSON.h"
 #import "RTCSessionDescription+JSON.h"
 
-static NSString * const kARDDefaultSTUNServerUrl =
-    @"stun:stun.l.google.com:19302";
-// TODO(tkchin): figure out a better username for CEOD statistics.
-static NSString * const kARDTurnRequestUrl =
-    @"https://computeengineondemand.appspot.com"
-    @"/turn?username=iapprtc&key=4080218913";
+static NSString * const kARDIceServerRequestUrl = @"https://appr.tc/params";
 
 static NSString * const kARDAppClientErrorDomain = @"ARDAppClient";
 static NSInteger const kARDAppClientErrorUnknown = -1;
@@ -133,21 +128,15 @@ static int const kKbpsMultiplier = 1000;
 @synthesize shouldUseLevelControl = _shouldUseLevelControl;
 
 - (instancetype)init {
-  if (self = [super init]) {
-    _roomServerClient = [[ARDAppEngineClient alloc] init];
-    NSURL *turnRequestURL = [NSURL URLWithString:kARDTurnRequestUrl];
-    _turnClient = [[ARDCEODTURNClient alloc] initWithURL:turnRequestURL];
-    [self configure];
-  }
-  return self;
+  return [self initWithDelegate:nil];
 }
 
 - (instancetype)initWithDelegate:(id<ARDAppClientDelegate>)delegate {
   if (self = [super init]) {
     _roomServerClient = [[ARDAppEngineClient alloc] init];
     _delegate = delegate;
-    NSURL *turnRequestURL = [NSURL URLWithString:kARDTurnRequestUrl];
-    _turnClient = [[ARDCEODTURNClient alloc] initWithURL:turnRequestURL];
+    NSURL *turnRequestURL = [NSURL URLWithString:kARDIceServerRequestUrl];
+    _turnClient = [[ARDTURNClient alloc] initWithURL:turnRequestURL];
     [self configure];
   }
   return self;
@@ -176,7 +165,7 @@ static int const kKbpsMultiplier = 1000;
 - (void)configure {
   _factory = [[RTCPeerConnectionFactory alloc] init];
   _messageQueue = [NSMutableArray array];
-  _iceServers = [NSMutableArray arrayWithObject:[self defaultSTUNServer]];
+  _iceServers = [NSMutableArray array];
   _fileLogger = [[RTCFileLogger alloc] init];
   [_fileLogger start];
 }
@@ -814,12 +803,6 @@ static int const kKbpsMultiplier = 1000;
   return constraints;
 }
 
-- (RTCIceServer *)defaultSTUNServer {
-  return [[RTCIceServer alloc] initWithURLStrings:@[kARDDefaultSTUNServerUrl]
-                                         username:@""
-                                       credential:@""];
-}
-
 #pragma mark - Errors
 
 + (NSError *)errorForJoinResultType:(ARDJoinResultType)resultType {