[SPDY] Incorporate latest framing changes from HTTP2 into SPDY 4 as SPDY 4a2.

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/bind.h"
 #include "base/bind_helpers.h"
@@ skipping 639 matching lines @@
     globals_->max_spdy_concurrent_streams_limit.set(
         GetSwitchValueAsInt(command_line, switches::kMaxSpdyConcurrentStreams));
   }
   if (command_line.HasSwitch(switches::kIgnoreUrlFetcherCertRequests))
     net::URLFetcher::SetIgnoreCertificateRequests(true);
 
   if (command_line.HasSwitch(switches::kUseSpdy)) {
     std::string spdy_mode =
         command_line.GetSwitchValueASCII(switches::kUseSpdy);
     EnableSpdy(spdy_mode);
-  } else if (command_line.HasSwitch(switches::kEnableSpdy4a1)) {
-    net::HttpStreamFactory::EnableNpnSpdy4a1();
   } else if (command_line.HasSwitch(switches::kDisableSpdy31)) {
     net::HttpStreamFactory::EnableNpnSpdy3();
   } else if (command_line.HasSwitch(switches::kEnableNpn)) {
     net::HttpStreamFactory::EnableNpnSpdy();
   } else if (command_line.HasSwitch(switches::kEnableNpnHttpOnly)) {
     net::HttpStreamFactory::EnableNpnHttpOnly();
   } else {
     // Use SPDY/3.1 by default.
     net::HttpStreamFactory::EnableNpnSpdy31();
   }
@@ skipping 241 matching lines @@
   globals_->system_request_context.reset(
       ConstructSystemRequestContext(globals_, net_log_));
 
   sdch_manager_->set_sdch_fetcher(
       new SdchDictionaryFetcher(system_url_request_context_getter_.get()));
 }
 
 void IOThread::UpdateDnsClientEnabled() {
   globals()->host_resolver->SetDnsClientEnabled(*dns_client_enabled_);
 }