Implement Token Binding negotiation TLS extension

net/socket/ssl_client_socket.h

Index: net/socket/ssl_client_socket.h
diff --git a/net/socket/ssl_client_socket.h b/net/socket/ssl_client_socket.h
index 67800602ee4c3ec24f4989c20b067ff36a9c7d7b..def5ff4cb3b573f7fa246ead51f8f89418101e3a 100644
--- a/net/socket/ssl_client_socket.h
+++ b/net/socket/ssl_client_socket.h
@@ -167,6 +167,10 @@ class NET_EXPORT SSLClientSocket : public SSLSocket {
       const SSLConfig& ssl_config,
       ChannelIDService* channel_id_service);
 
+  // Returns whether Token Binding is enabled.
+  static bool IsTokenBindingEnabled(const SSLConfig& ssl_config,
+                                    ChannelIDService* channel_id_service);
+
   // Determine if there is at least one enabled cipher suite that satisfies
   // Section 9.2 of the HTTP/2 specification.  Note that the server might still
   // pick an inadequate cipher suite.