Change QuicStreamRequest::Request() to take a preferred QuicVersion so that

net/http/http_server_properties.h

Index: net/http/http_server_properties.h
diff --git a/net/http/http_server_properties.h b/net/http/http_server_properties.h
index 49787f616c9e6d8a15975a7e762bdd6dfde06dbc..7ff4e5a82866235c1e5d3f78362f8384cdd4b783 100644
--- a/net/http/http_server_properties.h
+++ b/net/http/http_server_properties.h
@@ -175,6 +175,12 @@ class NET_EXPORT_PRIVATE AlternativeServiceInfo {
     return alternative_service_;
   }
 
+  NextProto protocol() const { return alternative_service_.protocol; }
+
+  HostPortPair host_port_pair() const {
+    return alternative_service_.host_port_pair();
+  }
+
   base::Time expiration() const { return expiration_; }
 
   const QuicVersionVector& advertised_versions() const {