Disable HTTP/2 over NPN (with OpenSSL).

chrome/browser/net/preconnect.cc

Index: chrome/browser/net/preconnect.cc
diff --git a/chrome/browser/net/preconnect.cc b/chrome/browser/net/preconnect.cc
index 17673c31bed256fdd2dc02dca27964b8938d7905..eb06625c9943441d4f90f8084d6337ec96f8de68 100644
--- a/chrome/browser/net/preconnect.cc
+++ b/chrome/browser/net/preconnect.cc
@@ -103,7 +103,8 @@ void PreconnectOnIOThread(const GURL& url,
   // Setup the SSL Configuration.
   net::SSLConfig ssl_config;
   session->ssl_config_service()->GetSSLConfig(&ssl_config);
-  session->GetNextProtos(&ssl_config.next_protos);
+  session->GetAlpnProtos(&ssl_config.alpn_protos);
+  session->GetNpnProtos(&ssl_config.npn_protos);
 
   // All preconnects should perform EV certificate verification.
   ssl_config.verify_ev_cert = true;