[SPDY] Do not advertise SPDY/2 by default

net/http/http_network_layer.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 "net/http/http_network_layer.h"
 
 #include "base/logging.h"
 #include "base/strings/string_number_conversions.h"
 #include "base/strings/string_split.h"
 #include "base/strings/string_util.h"
@@ skipping 24 matching lines @@
     HttpNetworkSession* session) {
   DCHECK(session);
 
   return new HttpNetworkLayer(session);
 }
 
 // static
 void HttpNetworkLayer::ForceAlternateProtocol() {
   PortAlternateProtocolPair pair;
   pair.port = 443;
-  pair.protocol = NPN_SPDY_2;
+  pair.protocol = NPN_SPDY_3;
   HttpServerPropertiesImpl::ForceAlternateProtocol(pair);
 }
 
 //-----------------------------------------------------------------------------
 
 int HttpNetworkLayer::CreateTransaction(RequestPriority priority,
                                         scoped_ptr<HttpTransaction>* trans,
                                         HttpTransactionDelegate* delegate) {
   if (suspended_)
     return ERR_NETWORK_IO_SUSPENDED;
@@ skipping 13 matching lines @@
 
   if (session_.get())
     session_->CloseIdleConnections();
 }
 
 void HttpNetworkLayer::OnResume() {
   suspended_ = false;
 }
 
 }  // namespace net