Add a new GetNegotiatedProtocol method to StreamSocket and implement in all subclasses.

remoting/jingle_glue/ssl_socket_adapter.cc

Index: remoting/jingle_glue/ssl_socket_adapter.cc
diff --git a/remoting/jingle_glue/ssl_socket_adapter.cc b/remoting/jingle_glue/ssl_socket_adapter.cc
index 5c3d2bf3dcbfcaac53faa97828c68636418887fe..5966396736589ab9e57e204f9225b2973a53b5dd 100644
--- a/remoting/jingle_glue/ssl_socket_adapter.cc
+++ b/remoting/jingle_glue/ssl_socket_adapter.cc
@@ -278,6 +278,11 @@ base::TimeDelta TransportSocket::GetConnectTimeMicros() const {
   return base::TimeDelta::FromMicroseconds(-1);
 }
 
+net::NextProto TransportSocket::GetNegotiatedProtocol() const {
+  NOTREACHED();
+  return net::kProtoUnknown;
+}
+
 int TransportSocket::Read(net::IOBuffer* buf, int buf_len,
                           const net::CompletionCallback& callback) {
   DCHECK(buf);