Enable SNI in ssl adapter.

Bug: webrtc:6973
Change-Id: I13d28cf41c586880bd7fea523005233921794cdf
Reviewed-on: https://chromium-review.googlesource.com/523024
Reviewed-by: Zeke Chin <tkchin@webrtc.org>
Reviewed-by: Sami Kalliomäki <sakal@webrtc.org>
Reviewed-by: Justin Uberti <juberti@chromium.org>
Reviewed-by: Taylor Brandstetter <deadbeef@webrtc.org>
Commit-Queue: Emad Omara <emadomara@google.com>
Cr-Commit-Position: refs/heads/master@{#18640}

webrtc/sdk/objc/Framework/Headers/WebRTC/RTCIceServer.h

@@ -36,6 +36,13 @@ RTC_EXPORT
  */
 @property(nonatomic, readonly) RTCTlsCertPolicy tlsCertPolicy;
 
+/**
+  If the URIs in |urls| only contain IP addresses, this field can be used
+  to indicate the hostname, which may be necessary for TLS (using the SNI
+  extension). If |urls| itself contains the hostname, this isn't necessary.
+ */
+@property(nonatomic, readonly, nullable) NSString *hostname;
+
 - (nonnull instancetype)init NS_UNAVAILABLE;
 
 /** Convenience initializer for a server with no authentication (e.g. STUN). */
@@ -53,11 +60,20 @@ RTC_EXPORT
  * Initialize an RTCIceServer with its associated URLs, optional username,
  * optional credential, and TLS cert policy.
  */
+- (instancetype)initWithURLStrings:(NSArray<NSString *> *)urlStrings
+                          username:(nullable NSString *)username
+                        credential:(nullable NSString *)credential
+                     tlsCertPolicy:(RTCTlsCertPolicy)tlsCertPolicy;
+
+/**
+ * Initialize an RTCIceServer with its associated URLs, optional username,
+ * optional credential, TLS cert policy and hostname.
+ */
 - (instancetype)initWithURLStrings:(NSArray<NSString *> *)urlStrings
                           username:(nullable NSString *)username
                         credential:(nullable NSString *)credential
                      tlsCertPolicy:(RTCTlsCertPolicy)tlsCertPolicy
-    NS_DESIGNATED_INITIALIZER;
+                          hostname:(nullable NSString *)hostname NS_DESIGNATED_INITIALIZER;
 
 @end