Remove about:flags#enable-spdy4 flag.

chrome/browser/io_thread.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/io_thread.h"
 
 #include <vector>
 
 #include "base/base64.h"
 #include "base/bind.h"
@@ skipping 1016 matching lines @@
 
   if (command_line.HasSwitch(switches::kEnableSpdy4)) {
     globals->next_protos.push_back(net::kProtoSPDY31);
     globals->next_protos.push_back(net::kProtoSPDY4_14);
     globals->next_protos.push_back(net::kProtoSPDY4);
     globals->use_alternate_protocols.set(true);
     return;
   }
   if (command_line.HasSwitch(switches::kEnableNpnHttpOnly)) {
     globals->use_alternate_protocols.set(false);
+    net::HttpStreamFactory::set_spdy_enabled(false);
     return;
   }
 
   // No SPDY command-line flags have been specified. Examine trial groups.
   if (spdy_trial_group.starts_with(kSpdyFieldTrialHoldbackGroupNamePrefix)) {
     net::HttpStreamFactory::set_spdy_enabled(false);
     return;
   }
   if (spdy_trial_group.starts_with(kSpdyFieldTrialSpdy31GroupNamePrefix)) {
     globals->next_protos.push_back(net::kProtoSPDY31);
@@ skipping 586 matching lines @@
   net::QuicVersionVector supported_versions = net::QuicSupportedVersions();
   for (size_t i = 0; i < supported_versions.size(); ++i) {
     net::QuicVersion version = supported_versions[i];
     if (net::QuicVersionToString(version) == quic_version) {
       return version;
     }
   }
 
   return net::QUIC_VERSION_UNSUPPORTED;
 }