Add Spdy4Experiment group.

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"
 #include "base/bind_helpers.h"
 #include "base/command_line.h"
 #include "base/compiler_specific.h"
 #include "base/debug/leak_tracker.h"
 #include "base/debug/trace_event.h"
 #include "base/logging.h"
 #include "base/metrics/field_trial.h"
 #include "base/prefs/pref_registry_simple.h"
 #include "base/prefs/pref_service.h"
 #include "base/stl_util.h"
 #include "base/strings/string_number_conversions.h"
+#include "base/strings/string_piece.h"
 #include "base/strings/string_split.h"
 #include "base/strings/string_util.h"
 #include "base/threading/sequenced_worker_pool.h"
 #include "base/threading/thread.h"
 #include "base/threading/worker_pool.h"
 #include "base/time/time.h"
 #include "build/build_config.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/net/async_dns_field_trial.h"
 #include "chrome/browser/net/chrome_net_log.h"
@@ skipping 92 matching lines @@
 const char kQuicFieldTrialPacingSuffix[] = "WithPacing";
 
 // The SPDY trial composes two different trial plus control groups:
 //  * A "holdback" group with SPDY disabled, and corresponding control
 //  (SPDY/3.1). The primary purpose of the holdback group is to encourage site
 //  operators to do feature detection rather than UA-sniffing. As such, this
 //  trial runs continuously.
 //  * A SPDY/4 experiment, for SPDY/4 (aka HTTP/2) vs SPDY/3.1 comparisons and
 //  eventual SPDY/4 deployment.
 const char kSpdyFieldTrialName[] = "SPDY";
-const char kSpdyFieldTrialHoldbackGroupName[] = "SpdyDisabled";
+const char kSpdyFieldTrialHoldbackGroupNamePrefix[] = "SpdyDisabled";
 const char kSpdyFieldTrialHoldbackControlGroupName[] = "Control";
-const char kSpdyFieldTrialSpdy4GroupName[] = "Spdy4Enabled";
+const char kSpdyFieldTrialSpdy31GroupNamePrefix[] = "Spdy31Enabled";
+const char kSpdyFieldTrialSpdy4GroupNamePrefix[] = "Spdy4Enabled";
 const char kSpdyFieldTrialSpdy4ControlGroupName[] = "Spdy4Control";
 
 // Field trial for Cache-Control: stale-while-revalidate directive.
 const char kStaleWhileRevalidateFieldTrialName[] = "StaleWhileRevalidate";
 
 #if defined(OS_MACOSX) && !defined(OS_IOS)
 void ObserveKeychainEvents() {
   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
   net::CertDatabase::GetInstance()->SetMessageLoopForKeychainEvents();
 }
@@ skipping 678 matching lines @@
       base::FieldTrialList::FindFullName(kTCPFastOpenFieldTrialName);
   if (trial_group == kTCPFastOpenHttpsEnabledGroupName)
     globals_->enable_tcp_fast_open_for_ssl.set(true);
   bool always_enable_if_supported =
       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,
+void IOThread::ConfigureSpdyFromTrial(base::StringPiece spdy_trial_group,
                                       Globals* globals) {
-  if (spdy_trial_group == kSpdyFieldTrialHoldbackGroupName) {
+  if (spdy_trial_group.starts_with(kSpdyFieldTrialHoldbackGroupNamePrefix)) {
     // TODO(jgraettinger): Use net::NextProtosHttpOnly() instead?
     net::HttpStreamFactory::set_spdy_enabled(false);
   } else if (spdy_trial_group == kSpdyFieldTrialHoldbackControlGroupName) {
     // Use the current SPDY default (SPDY/3.1).
     globals->next_protos = net::NextProtosSpdy31();
     globals->use_alternate_protocols.set(true);
-  } else if (spdy_trial_group == kSpdyFieldTrialSpdy4GroupName) {
+  } else if (spdy_trial_group.starts_with(
+                 kSpdyFieldTrialSpdy31GroupNamePrefix)) {
+    globals->next_protos = net::NextProtosSpdy4Http2();
+    globals->use_alternate_protocols.set(true);
+  } else if (spdy_trial_group.starts_with(
+                 kSpdyFieldTrialSpdy4GroupNamePrefix)) {
     globals->next_protos = net::NextProtosSpdy4Http2();
     globals->use_alternate_protocols.set(true);
   } else if (spdy_trial_group == kSpdyFieldTrialSpdy4ControlGroupName) {

[Ryan Hamilton, 2014/10/30 21:33:32]

If you named the spdy/4 control group as:

Spdy31EnabledAsSpdy4ControlGroup, then you could avoid this "else if" block
altogether.

If you make this change in finch after this CL lands, you could then land a
followup removing this block.

     // This control group is pinned at SPDY/3.1.
     globals->next_protos = net::NextProtosSpdy31();
     globals->use_alternate_protocols.set(true);
   } else {
     // Use the current SPDY default (SPDY/3.1).
     globals->next_protos = net::NextProtosSpdy31();
     globals->use_alternate_protocols.set(true);
   }
 }
 
@@ skipping 574 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;
 }