Plumbing for TCP FastOpen field trial and enables it for SSL sockets.

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 97 matching lines @@
 
 using content::BrowserThread;
 
 class SafeBrowsingURLRequestContext;
 
 // The IOThread object must outlive any tasks posted to the IO thread before the
 // Quit task, so base::Bind() calls are not refcounted.
 
 namespace {
 
+const char kTCPFastOpenForSSLFieldTrialName[] = "TCPFastOpenEnabledForSSL";
+
 const char kQuicFieldTrialName[] = "QUIC";
 const char kQuicFieldTrialEnabledGroupName[] = "Enabled";
 const char kQuicFieldTrialHttpsEnabledGroupName[] = "HttpsEnabled";
 const char kQuicFieldTrialPacketLengthSuffix[] = "BytePackets";
 const char kQuicFieldTrialPacingSuffix[] = "WithPacing";
 const char kQuicFieldTrialTimeBasedLossDetectionSuffix[] =
     "WithTimeBasedLossDetection";
 
 // The SPDY trial composes two different trial plus control groups:
 //  * A "holdback" group with SPDY disabled, and corresponding control
@@ skipping 704 matching lines @@
     } else {
       // No SPDY command-line flags have been specified. Examine trial groups.
       ConfigureSpdyFromTrial(
           base::FieldTrialList::FindFullName(kSpdyFieldTrialName), globals_);
     }
 
     if (command_line.HasSwitch(switches::kEnableWebSocketOverSpdy))
       globals_->enable_websocket_over_spdy.set(true);
   }
 
+  ConfigureTCPFastOpen(command_line);
+
   // TODO(rch): Make the client socket factory a per-network session
   // instance, constructed from a NetworkSession::Params, to allow us
   // to move this option to IOThread::Globals &
   // HttpNetworkSession::Params.
+}
 
+void IOThread::ConfigureTCPFastOpen(const CommandLine& command_line) {
+  const std::string trial_group =
+      base::FieldTrialList::FindFullName(kTCPFastOpenForSSLFieldTrialName);
+  if (trial_group == kTCPFastOpenForSSLFieldTrialName)
+    globals_->enable_tcp_fast_open_for_ssl.set(true);

[Randy Smith (Not in Mondays), 2014/09/10 18:57:06]

This looks wrong to me--it looks like you're conflating the field trial name
with the group within the trial that you're going to use.  Usually field trials
have 3 groups: Enabled/Disabled/Default (often named just that) and you select
among them.  You can take a look at how I'm doing SDCH in chrome_browser_main.cc
(search for "SDCH" to see what I mean.

More generally, I'd recommend you do the finch bug to setup a field trial, get a
finch ambassador assigned, and ask them to review this CL.  They often have
preferences about how you do things, and catching them earlier rather than later
is helpful.

[Jana, 2014/09/11 20:04:59]

Yes, you are right -- I had conflated these things. I've separated them out, now
that I (yet again) understand Finch better. PTAL.

   bool always_enable_if_supported =
-    command_line.HasSwitch(switches::kEnableTcpFastOpen);
+      command_line.HasSwitch(switches::kEnableTcpFastOpen);
   // Check for OS support of TCP FastOpen, and turn it on for all connections
   // if indicated by user.
   net::CheckSupportAndMaybeEnableTCPFastOpen(always_enable_if_supported);
 }
 
 void IOThread::ConfigureSpdyFromTrial(const std::string& spdy_trial_group,
                                       Globals* globals) {
   if (spdy_trial_group == kSpdyFieldTrialHoldbackGroupName) {
     // TODO(jgraettinger): Use net::NextProtosHttpOnly() instead?
     net::HttpStreamFactory::set_spdy_enabled(false);
@@ skipping 148 matching lines @@
   params->http_auth_handler_factory = globals.http_auth_handler_factory.get();
   params->http_server_properties =
       globals.http_server_properties->GetWeakPtr();
   params->network_delegate = globals.system_network_delegate.get();
   params->host_mapping_rules = globals.host_mapping_rules.get();
   params->enable_ssl_connect_job_waiting =
       globals.enable_ssl_connect_job_waiting;
   params->ignore_certificate_errors = globals.ignore_certificate_errors;
   params->testing_fixed_http_port = globals.testing_fixed_http_port;
   params->testing_fixed_https_port = globals.testing_fixed_https_port;
+  globals.enable_tcp_fast_open_for_ssl.CopyToIfSet(
+      &params->enable_tcp_fast_open_for_ssl);
 
   globals.initial_max_spdy_concurrent_streams.CopyToIfSet(
       &params->spdy_initial_max_concurrent_streams);
   globals.force_spdy_single_domain.CopyToIfSet(
       &params->force_spdy_single_domain);
   globals.enable_spdy_compression.CopyToIfSet(
       &params->enable_spdy_compression);
   globals.enable_spdy_ping_based_connection_checking.CopyToIfSet(
       &params->enable_spdy_ping_based_connection_checking);
   globals.spdy_default_protocol.CopyToIfSet(
@@ skipping 372 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;
 }