chrome/browser/io_thread.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "chrome/browser/io_thread.h"
   6
   7 #include <vector>
   8
   9 #include "base/base64.h"
  10 #include "base/bind.h"
  11 #include "base/bind_helpers.h"
  12 #include "base/command_line.h"
  13 #include "base/compiler_specific.h"
  14 #include "base/debug/leak_tracker.h"
  15 #include "base/logging.h"
  16 #include "base/metrics/field_trial.h"
  17 #include "base/prefs/pref_registry_simple.h"
  18 #include "base/prefs/pref_service.h"
  19 #include "base/profiler/scoped_tracker.h"
  20 #include "base/stl_util.h"
  21 #include "base/strings/string_number_conversions.h"
  22 #include "base/strings/string_piece.h"
  23 #include "base/strings/string_split.h"
  24 #include "base/strings/string_util.h"
  25 #include "base/threading/sequenced_worker_pool.h"
  26 #include "base/threading/thread.h"
  27 #include "base/threading/worker_pool.h"
  28 #include "base/time/time.h"
  29 #include "base/trace_event/trace_event.h"
  30 #include "build/build_config.h"
  31 #include "chrome/browser/browser_process.h"
  32 #include "chrome/browser/net/async_dns_field_trial.h"
  33 #include "chrome/browser/net/chrome_net_log.h"
  34 #include "chrome/browser/net/chrome_network_delegate.h"
  35 #include "chrome/browser/net/connect_interceptor.h"
  36 #include "chrome/browser/net/dns_probe_service.h"
  37 #include "chrome/browser/net/pref_proxy_config_tracker.h"
  38 #include "chrome/browser/net/proxy_service_factory.h"
  39 #include "chrome/common/channel_info.h"
  40 #include "chrome/common/chrome_content_client.h"
  41 #include "chrome/common/chrome_switches.h"
  42 #include "chrome/common/pref_names.h"
  43 #include "components/data_reduction_proxy/core/browser/data_reduction_proxy_prefs.h"
  44 #include "components/data_reduction_proxy/core/common/data_reduction_proxy_params.h"
  45 #include "components/policy/core/common/policy_service.h"
  46 #include "components/variations/variations_associated_data.h"
  47 #include "components/version_info/version_info.h"
  48 #include "content/public/browser/browser_thread.h"
  49 #include "content/public/browser/cookie_store_factory.h"
  50 #include "content/public/common/user_agent.h"
  51 #include "net/base/host_mapping_rules.h"
  52 #include "net/base/net_util.h"
  53 #include "net/base/network_quality_estimator.h"
  54 #include "net/base/sdch_manager.h"
  55 #include "net/cert/cert_policy_enforcer.h"
  56 #include "net/cert/cert_verifier.h"
  57 #include "net/cert/cert_verify_proc.h"
  58 #include "net/cert/ct_known_logs.h"
  59 #include "net/cert/ct_known_logs_static.h"
  60 #include "net/cert/ct_log_verifier.h"
  61 #include "net/cert/ct_verifier.h"
  62 #include "net/cert/multi_log_ct_verifier.h"
  63 #include "net/cert/multi_threaded_cert_verifier.h"
  64 #include "net/cookies/cookie_store.h"
  65 #include "net/dns/host_cache.h"
  66 #include "net/dns/host_resolver.h"
  67 #include "net/dns/mapped_host_resolver.h"
  68 #include "net/ftp/ftp_network_layer.h"
  69 #include "net/http/http_auth_filter.h"
  70 #include "net/http/http_auth_handler_factory.h"
  71 #include "net/http/http_network_layer.h"
  72 #include "net/http/http_server_properties_impl.h"
  73 #include "net/proxy/proxy_config_service.h"
  74 #include "net/proxy/proxy_script_fetcher_impl.h"
  75 #include "net/proxy/proxy_service.h"
  76 #include "net/quic/crypto/crypto_protocol.h"
  77 #include "net/quic/quic_protocol.h"
  78 #include "net/quic/quic_utils.h"
  79 #include "net/socket/tcp_client_socket.h"
  80 #include "net/spdy/spdy_session.h"
  81 #include "net/ssl/channel_id_service.h"
  82 #include "net/ssl/default_channel_id_store.h"
  83 #include "net/url_request/data_protocol_handler.h"
  84 #include "net/url_request/file_protocol_handler.h"
  85 #include "net/url_request/ftp_protocol_handler.h"
  86 #include "net/url_request/static_http_user_agent_settings.h"
  87 #include "net/url_request/url_fetcher.h"
  88 #include "net/url_request/url_request_backoff_manager.h"
  89 #include "net/url_request/url_request_context.h"
  90 #include "net/url_request/url_request_context_getter.h"
  91 #include "net/url_request/url_request_job_factory_impl.h"
  92 #include "url/url_constants.h"
  93
  94 #if defined(ENABLE_CONFIGURATION_POLICY)
  95 #include "policy/policy_constants.h"
  96 #endif
  97
  98 #if defined(ENABLE_EXTENSIONS)
  99 #include "chrome/browser/extensions/event_router_forwarder.h"
 100 #endif
 101
 102 #if defined(USE_NSS_CERTS) || defined(OS_IOS)
 103 #include "net/cert_net/nss_ocsp.h"
 104 #endif
 105
 106 #if defined(OS_ANDROID)
 107 #include "base/android/build_info.h"
 108 #endif
 109
 110 #if defined(OS_CHROMEOS)
 111 #include "chrome/browser/chromeos/net/cert_verify_proc_chromeos.h"
 112 #include "chromeos/network/host_resolver_impl_chromeos.h"
 113 #endif
 114
 115 using content::BrowserThread;
 116
 117 class SafeBrowsingURLRequestContext;
 118
 119 // The IOThread object must outlive any tasks posted to the IO thread before the
 120 // Quit task, so base::Bind() calls are not refcounted.
 121
 122 namespace {
 123
 124 const char kTCPFastOpenFieldTrialName[] = "TCPFastOpen";
 125 const char kTCPFastOpenHttpsEnabledGroupName[] = "HttpsEnabled";
 126
 127 const char kQuicFieldTrialName[] = "QUIC";
 128 const char kQuicFieldTrialEnabledGroupName[] = "Enabled";
 129 const char kQuicFieldTrialHttpsEnabledGroupName[] = "HttpsEnabled";
 130
 131 // The SPDY trial composes two different trial plus control groups:
 132 //  * A "holdback" group with SPDY disabled, and corresponding control
 133 //  (SPDY/3.1). The primary purpose of the holdback group is to encourage site
 134 //  operators to do feature detection rather than UA-sniffing. As such, this
 135 //  trial runs continuously.
 136 //  * A SPDY/4 experiment, for SPDY/4 (aka HTTP/2) vs SPDY/3.1 comparisons and
 137 //  eventual SPDY/4 deployment.
 138 const char kSpdyFieldTrialName[] = "SPDY";
 139 const char kSpdyFieldTrialHoldbackGroupNamePrefix[] = "SpdyDisabled";
 140 const char kSpdyFieldTrialSpdy31GroupNamePrefix[] = "Spdy31Enabled";
 141 const char kSpdyFieldTrialSpdy4GroupNamePrefix[] = "Spdy4Enabled";
 142 const char kSpdyFieldTrialParametrizedPrefix[] = "Parametrized";
 143
 144 // Field trial for network quality estimator. Seeds RTT and downstream
 145 // throughput observations with values that correspond to the connection type
 146 // determined by the operating system.
 147 const char kNetworkQualityEstimatorFieldTrialName[] = "NetworkQualityEstimator";
 148
 149 #if defined(OS_MACOSX) && !defined(OS_IOS)
 150 void ObserveKeychainEvents() {
 151   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 152   net::CertDatabase::GetInstance()->SetMessageLoopForKeychainEvents();
 153 }
 154 #endif
 155
 156 // Used for the "system" URLRequestContext.
 157 class SystemURLRequestContext : public net::URLRequestContext {
 158  public:
 159   SystemURLRequestContext() {
 160 #if defined(USE_NSS_CERTS) || defined(OS_IOS)
 161     net::SetURLRequestContextForNSSHttpIO(this);
 162 #endif
 163   }
 164
 165  private:
 166   ~SystemURLRequestContext() override {
 167     AssertNoURLRequests();
 168 #if defined(USE_NSS_CERTS) || defined(OS_IOS)
 169     net::SetURLRequestContextForNSSHttpIO(NULL);
 170 #endif
 171   }
 172 };
 173
 174 scoped_ptr<net::HostResolver> CreateGlobalHostResolver(net::NetLog* net_log) {
 175   TRACE_EVENT0("startup", "IOThread::CreateGlobalHostResolver");
 176   const base::CommandLine& command_line =
 177       *base::CommandLine::ForCurrentProcess();
 178
 179   net::HostResolver::Options options;
 180
 181   // Use the retry attempts override from the command-line, if any.
 182   if (command_line.HasSwitch(switches::kHostResolverRetryAttempts)) {
 183     std::string s =
 184         command_line.GetSwitchValueASCII(switches::kHostResolverRetryAttempts);
 185     // Parse the switch (it should be a non-negative integer).
 186     int n;
 187     if (base::StringToInt(s, &n) && n >= 0) {
 188       options.max_retry_attempts = static_cast<size_t>(n);
 189     } else {
 190       LOG(ERROR) << "Invalid switch for host resolver retry attempts: " << s;
 191     }
 192   }
 193
 194   scoped_ptr<net::HostResolver> global_host_resolver;
 195 #if defined OS_CHROMEOS
 196   global_host_resolver =
 197       chromeos::HostResolverImplChromeOS::CreateSystemResolver(options,
 198                                                                net_log);
 199 #else
 200   global_host_resolver =
 201       net::HostResolver::CreateSystemResolver(options, net_log);
 202 #endif
 203
 204   // If hostname remappings were specified on the command-line, layer these
 205   // rules on top of the real host resolver. This allows forwarding all requests
 206   // through a designated test server.
 207   if (!command_line.HasSwitch(switches::kHostResolverRules))
 208     return global_host_resolver.Pass();
 209
 210   scoped_ptr<net::MappedHostResolver> remapped_resolver(
 211       new net::MappedHostResolver(global_host_resolver.Pass()));
 212   remapped_resolver->SetRulesFromString(
 213       command_line.GetSwitchValueASCII(switches::kHostResolverRules));
 214   return remapped_resolver.Pass();
 215 }
 216
 217 // TODO(willchan): Remove proxy script fetcher context since it's not necessary
 218 // now that I got rid of refcounting URLRequestContexts.
 219 // See IOThread::Globals for details.
 220 net::URLRequestContext*
 221 ConstructProxyScriptFetcherContext(IOThread::Globals* globals,
 222                                    net::NetLog* net_log) {
 223   net::URLRequestContext* context = new net::URLRequestContext;
 224   context->set_net_log(net_log);
 225   context->set_host_resolver(globals->host_resolver.get());
 226   context->set_cert_verifier(globals->cert_verifier.get());
 227   context->set_transport_security_state(
 228       globals->transport_security_state.get());
 229   context->set_cert_transparency_verifier(
 230       globals->cert_transparency_verifier.get());
 231   context->set_http_auth_handler_factory(
 232       globals->http_auth_handler_factory.get());
 233   context->set_proxy_service(globals->proxy_script_fetcher_proxy_service.get());
 234   context->set_http_transaction_factory(
 235       globals->proxy_script_fetcher_http_transaction_factory.get());
 236   context->set_job_factory(
 237       globals->proxy_script_fetcher_url_request_job_factory.get());
 238   context->set_cookie_store(globals->system_cookie_store.get());
 239   context->set_channel_id_service(
 240       globals->system_channel_id_service.get());
 241   context->set_network_delegate(globals->system_network_delegate.get());
 242   context->set_http_user_agent_settings(
 243       globals->http_user_agent_settings.get());
 244   // TODO(rtenneti): We should probably use HttpServerPropertiesManager for the
 245   // system URLRequestContext too. There's no reason this should be tied to a
 246   // profile.
 247   return context;
 248 }
 249
 250 net::URLRequestContext*
 251 ConstructSystemRequestContext(IOThread::Globals* globals,
 252                               net::NetLog* net_log) {
 253   net::URLRequestContext* context = new SystemURLRequestContext;
 254   context->set_net_log(net_log);
 255   context->set_host_resolver(globals->host_resolver.get());
 256   context->set_cert_verifier(globals->cert_verifier.get());
 257   context->set_transport_security_state(
 258       globals->transport_security_state.get());
 259   context->set_cert_transparency_verifier(
 260       globals->cert_transparency_verifier.get());
 261   context->set_http_auth_handler_factory(
 262       globals->http_auth_handler_factory.get());
 263   context->set_proxy_service(globals->system_proxy_service.get());
 264   context->set_http_transaction_factory(
 265       globals->system_http_transaction_factory.get());
 266   context->set_job_factory(globals->system_url_request_job_factory.get());
 267   context->set_cookie_store(globals->system_cookie_store.get());
 268   context->set_channel_id_service(
 269       globals->system_channel_id_service.get());
 270   context->set_network_delegate(globals->system_network_delegate.get());
 271   context->set_http_user_agent_settings(
 272       globals->http_user_agent_settings.get());
 273   context->set_network_quality_estimator(
 274       globals->network_quality_estimator.get());
 275   context->set_backoff_manager(globals->url_request_backoff_manager.get());
 276   return context;
 277 }
 278
 279 int GetSwitchValueAsInt(const base::CommandLine& command_line,
 280                         const std::string& switch_name) {
 281   int value;
 282   if (!base::StringToInt(command_line.GetSwitchValueASCII(switch_name),
 283                          &value)) {
 284     return 0;
 285   }
 286   return value;
 287 }
 288
 289 // Returns the value associated with |key| in |params| or "" if the
 290 // key is not present in the map.
 291 const std::string& GetVariationParam(
 292     const std::map<std::string, std::string>& params,
 293     const std::string& key) {
 294   std::map<std::string, std::string>::const_iterator it = params.find(key);
 295   if (it == params.end())
 296     return base::EmptyString();
 297
 298   return it->second;
 299 }
 300
 301 // Parse kUseSpdy command line flag options, which may contain the following:
 302 //
 303 //   "off"                      : Disables SPDY support entirely.
 304 //   "no-ping"                  : Disables SPDY ping connection testing.
 305 //   "exclude=<host>"           : Disables SPDY support for the host <host>.
 306 //   "no-compress"              : Disables SPDY header compression.
 307 //   "no-alt-protocols          : Disables alternate protocol support.
 308 //   "init-max-streams=<limit>" : Specifies the maximum number of concurrent
 309 //                                streams for a SPDY session, unless the
 310 //                                specifies a different value via SETTINGS.
 311 void ConfigureSpdyGlobalsFromUseSpdyArgument(const std::string& mode,
 312                                              IOThread::Globals* globals) {
 313   static const char kOff[] = "off";
 314   static const char kDisablePing[] = "no-ping";
 315   static const char kExclude[] = "exclude";  // Hosts to exclude
 316   static const char kDisableCompression[] = "no-compress";
 317   static const char kDisableAltProtocols[] = "no-alt-protocols";
 318   static const char kInitialMaxConcurrentStreams[] = "init-max-streams";
 319
 320   for (const base::StringPiece& element : base::SplitStringPiece(
 321            mode, ",", base::TRIM_WHITESPACE, base::SPLIT_WANT_ALL)) {
 322     std::vector<base::StringPiece> name_value = base::SplitStringPiece(
 323         element, "=", base::TRIM_WHITESPACE, base::SPLIT_WANT_ALL);
 324     const base::StringPiece option =
 325         name_value.size() > 0 ? name_value[0] : base::StringPiece();
 326     const base::StringPiece value =
 327         name_value.size() > 1 ? name_value[1] : base::StringPiece();
 328
 329     if (option == kOff) {
 330       net::HttpStreamFactory::set_spdy_enabled(false);
 331       continue;
 332     }
 333     if (option == kDisablePing) {
 334       globals->enable_spdy_ping_based_connection_checking.set(false);
 335       continue;
 336     }
 337     if (option == kExclude) {
 338       globals->forced_spdy_exclusions.insert(
 339           net::HostPortPair::FromURL(GURL(value.as_string())));
 340       continue;
 341     }
 342     if (option == kDisableCompression) {
 343       globals->enable_spdy_compression.set(false);
 344       continue;
 345     }
 346     if (option == kDisableAltProtocols) {
 347       globals->use_alternate_protocols.set(false);
 348       continue;
 349     }
 350     if (option == kInitialMaxConcurrentStreams) {
 351       int streams;
 352       if (base::StringToInt(value, &streams)) {
 353         globals->initial_max_spdy_concurrent_streams.set(streams);
 354         continue;
 355       }
 356     }
 357     LOG(DFATAL) << "Unrecognized spdy option: " << option.as_string();
 358   }
 359 }
 360
 361 }  // namespace
 362
 363 class IOThread::LoggingNetworkChangeObserver
 364     : public net::NetworkChangeNotifier::IPAddressObserver,
 365       public net::NetworkChangeNotifier::ConnectionTypeObserver,
 366       public net::NetworkChangeNotifier::NetworkChangeObserver {
 367  public:
 368   // |net_log| must remain valid throughout our lifetime.
 369   explicit LoggingNetworkChangeObserver(net::NetLog* net_log)
 370       : net_log_(net_log) {
 371     net::NetworkChangeNotifier::AddIPAddressObserver(this);
 372     net::NetworkChangeNotifier::AddConnectionTypeObserver(this);
 373     net::NetworkChangeNotifier::AddNetworkChangeObserver(this);
 374   }
 375
 376   ~LoggingNetworkChangeObserver() override {
 377     net::NetworkChangeNotifier::RemoveIPAddressObserver(this);
 378     net::NetworkChangeNotifier::RemoveConnectionTypeObserver(this);
 379     net::NetworkChangeNotifier::RemoveNetworkChangeObserver(this);
 380   }
 381
 382   // NetworkChangeNotifier::IPAddressObserver implementation.
 383   void OnIPAddressChanged() override {
 384     VLOG(1) << "Observed a change to the network IP addresses";
 385
 386     net_log_->AddGlobalEntry(net::NetLog::TYPE_NETWORK_IP_ADDRESSES_CHANGED);
 387   }
 388
 389   // NetworkChangeNotifier::ConnectionTypeObserver implementation.
 390   void OnConnectionTypeChanged(
 391       net::NetworkChangeNotifier::ConnectionType type) override {
 392     std::string type_as_string =
 393         net::NetworkChangeNotifier::ConnectionTypeToString(type);
 394
 395     VLOG(1) << "Observed a change to network connectivity state "
 396             << type_as_string;
 397
 398     net_log_->AddGlobalEntry(
 399         net::NetLog::TYPE_NETWORK_CONNECTIVITY_CHANGED,
 400         net::NetLog::StringCallback("new_connection_type", &type_as_string));
 401   }
 402
 403   // NetworkChangeNotifier::NetworkChangeObserver implementation.
 404   void OnNetworkChanged(
 405       net::NetworkChangeNotifier::ConnectionType type) override {
 406     std::string type_as_string =
 407         net::NetworkChangeNotifier::ConnectionTypeToString(type);
 408
 409     VLOG(1) << "Observed a network change to state " << type_as_string;
 410
 411     net_log_->AddGlobalEntry(
 412         net::NetLog::TYPE_NETWORK_CHANGED,
 413         net::NetLog::StringCallback("new_connection_type", &type_as_string));
 414   }
 415
 416  private:
 417   net::NetLog* net_log_;
 418   DISALLOW_COPY_AND_ASSIGN(LoggingNetworkChangeObserver);
 419 };
 420
 421 class SystemURLRequestContextGetter : public net::URLRequestContextGetter {
 422  public:
 423   explicit SystemURLRequestContextGetter(IOThread* io_thread);
 424
 425   // Implementation for net::UrlRequestContextGetter.
 426   net::URLRequestContext* GetURLRequestContext() override;
 427   scoped_refptr<base::SingleThreadTaskRunner> GetNetworkTaskRunner()
 428       const override;
 429
 430  protected:
 431   ~SystemURLRequestContextGetter() override;
 432
 433  private:
 434   IOThread* const io_thread_;  // Weak pointer, owned by BrowserProcess.
 435   scoped_refptr<base::SingleThreadTaskRunner> network_task_runner_;
 436
 437   base::debug::LeakTracker<SystemURLRequestContextGetter> leak_tracker_;
 438 };
 439
 440 SystemURLRequestContextGetter::SystemURLRequestContextGetter(
 441     IOThread* io_thread)
 442     : io_thread_(io_thread),
 443       network_task_runner_(
 444           BrowserThread::GetMessageLoopProxyForThread(BrowserThread::IO)) {
 445 }
 446
 447 SystemURLRequestContextGetter::~SystemURLRequestContextGetter() {}
 448
 449 net::URLRequestContext* SystemURLRequestContextGetter::GetURLRequestContext() {
 450   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
 451   DCHECK(io_thread_->globals()->system_request_context.get());
 452
 453   return io_thread_->globals()->system_request_context.get();
 454 }
 455
 456 scoped_refptr<base::SingleThreadTaskRunner>
 457 SystemURLRequestContextGetter::GetNetworkTaskRunner() const {
 458   return network_task_runner_;
 459 }
 460
 461 IOThread::Globals::
 462 SystemRequestContextLeakChecker::SystemRequestContextLeakChecker(
 463     Globals* globals)
 464     : globals_(globals) {
 465   DCHECK(globals_);
 466 }
 467
 468 IOThread::Globals::
 469 SystemRequestContextLeakChecker::~SystemRequestContextLeakChecker() {
 470   if (globals_->system_request_context.get())
 471     globals_->system_request_context->AssertNoURLRequests();
 472 }
 473
 474 IOThread::Globals::Globals()
 475     : system_request_context_leak_checker(this),
 476       ignore_certificate_errors(false),
 477       testing_fixed_http_port(0),
 478       testing_fixed_https_port(0),
 479       enable_user_alternate_protocol_ports(false) {
 480 }
 481
 482 IOThread::Globals::~Globals() {}
 483
 484 // |local_state| is passed in explicitly in order to (1) reduce implicit
 485 // dependencies and (2) make IOThread more flexible for testing.
 486 IOThread::IOThread(
 487     PrefService* local_state,
 488     policy::PolicyService* policy_service,
 489     ChromeNetLog* net_log,
 490     extensions::EventRouterForwarder* extension_event_router_forwarder)
 491     : net_log_(net_log),
 492 #if defined(ENABLE_EXTENSIONS)
 493       extension_event_router_forwarder_(extension_event_router_forwarder),
 494 #endif
 495       globals_(NULL),
 496       is_spdy_disabled_by_policy_(false),
 497       is_quic_allowed_by_policy_(true),
 498       creation_time_(base::TimeTicks::Now()),
 499       weak_factory_(this) {
 500   auth_schemes_ = local_state->GetString(prefs::kAuthSchemes);
 501   negotiate_disable_cname_lookup_ = local_state->GetBoolean(
 502       prefs::kDisableAuthNegotiateCnameLookup);
 503   negotiate_enable_port_ = local_state->GetBoolean(
 504       prefs::kEnableAuthNegotiatePort);
 505   auth_server_whitelist_ = local_state->GetString(prefs::kAuthServerWhitelist);
 506   auth_delegate_whitelist_ = local_state->GetString(
 507       prefs::kAuthNegotiateDelegateWhitelist);
 508   gssapi_library_name_ = local_state->GetString(prefs::kGSSAPILibraryName);
 509   auth_android_negotiate_account_type_ =
 510       local_state->GetString(prefs::kAuthAndroidNegotiateAccountType);
 511   pref_proxy_config_tracker_.reset(
 512       ProxyServiceFactory::CreatePrefProxyConfigTrackerOfLocalState(
 513           local_state));
 514   ChromeNetworkDelegate::InitializePrefsOnUIThread(
 515       &system_enable_referrers_,
 516       NULL,
 517       NULL,
 518       NULL,
 519       local_state);
 520   ssl_config_service_manager_.reset(
 521       SSLConfigServiceManager::CreateDefaultManager(local_state));
 522
 523   base::Value* dns_client_enabled_default = new base::FundamentalValue(
 524       chrome_browser_net::ConfigureAsyncDnsFieldTrial());
 525   local_state->SetDefaultPrefValue(prefs::kBuiltInDnsClientEnabled,
 526                                    dns_client_enabled_default);
 527   chrome_browser_net::LogAsyncDnsPrefSource(
 528       local_state->FindPreference(prefs::kBuiltInDnsClientEnabled));
 529
 530   dns_client_enabled_.Init(prefs::kBuiltInDnsClientEnabled,
 531                            local_state,
 532                            base::Bind(&IOThread::UpdateDnsClientEnabled,
 533                                       base::Unretained(this)));
 534   dns_client_enabled_.MoveToThread(
 535       BrowserThread::GetMessageLoopProxyForThread(BrowserThread::IO));
 536
 537   quick_check_enabled_.Init(prefs::kQuickCheckEnabled,
 538                             local_state);
 539   quick_check_enabled_.MoveToThread(
 540       BrowserThread::GetMessageLoopProxyForThread(BrowserThread::IO));
 541
 542 #if defined(ENABLE_CONFIGURATION_POLICY)
 543   is_spdy_disabled_by_policy_ = policy_service->GetPolicies(
 544       policy::PolicyNamespace(policy::POLICY_DOMAIN_CHROME, std::string())).Get(
 545           policy::key::kDisableSpdy) != NULL;
 546
 547   const base::Value* value = policy_service->GetPolicies(
 548       policy::PolicyNamespace(policy::POLICY_DOMAIN_CHROME,
 549       std::string())).GetValue(policy::key::kQuicAllowed);
 550   if (value)
 551     value->GetAsBoolean(&is_quic_allowed_by_policy_);
 552 #endif  // ENABLE_CONFIGURATION_POLICY
 553
 554   BrowserThread::SetDelegate(BrowserThread::IO, this);
 555 }
 556
 557 IOThread::~IOThread() {
 558   // This isn't needed for production code, but in tests, IOThread may
 559   // be multiply constructed.
 560   BrowserThread::SetDelegate(BrowserThread::IO, NULL);
 561
 562   pref_proxy_config_tracker_->DetachFromPrefService();
 563   DCHECK(!globals_);
 564 }
 565
 566 IOThread::Globals* IOThread::globals() {
 567   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
 568   return globals_;
 569 }
 570
 571 void IOThread::SetGlobalsForTesting(Globals* globals) {
 572   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
 573   DCHECK(!globals || !globals_);
 574   globals_ = globals;
 575 }
 576
 577 ChromeNetLog* IOThread::net_log() {
 578   return net_log_;
 579 }
 580
 581 void IOThread::ChangedToOnTheRecord() {
 582   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 583   BrowserThread::PostTask(
 584       BrowserThread::IO,
 585       FROM_HERE,
 586       base::Bind(&IOThread::ChangedToOnTheRecordOnIOThread,
 587                  base::Unretained(this)));
 588 }
 589
 590 net::URLRequestContextGetter* IOThread::system_url_request_context_getter() {
 591   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::UI));
 592   if (!system_url_request_context_getter_.get()) {
 593     InitSystemRequestContext();
 594   }
 595   return system_url_request_context_getter_.get();
 596 }
 597
 598 void IOThread::Init() {
 599   // TODO(erikchen): Remove ScopedTracker below once http://crbug.com/466432
 600   // is fixed.
 601   tracked_objects::ScopedTracker tracking_profile1(
 602       FROM_HERE_WITH_EXPLICIT_FUNCTION("466432 IOThread::InitAsync::Start"));
 603   TRACE_EVENT0("startup", "IOThread::InitAsync");
 604   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
 605
 606 #if defined(USE_NSS_CERTS) || defined(OS_IOS)
 607   net::SetMessageLoopForNSSHttpIO();
 608 #endif
 609
 610   // TODO(erikchen): Remove ScopedTracker below once http://crbug.com/466432
 611   // is fixed.
 612   tracked_objects::ScopedTracker tracking_profile2(
 613       FROM_HERE_WITH_EXPLICIT_FUNCTION(
 614           "466432 IOThread::InitAsync::CommandLineForCurrentProcess"));
 615   const base::CommandLine& command_line =
 616       *base::CommandLine::ForCurrentProcess();
 617
 618   DCHECK(!globals_);
 619   globals_ = new Globals;
 620
 621   // Add an observer that will emit network change events to the ChromeNetLog.
 622   // Assuming NetworkChangeNotifier dispatches in FIFO order, we should be
 623   // logging the network change before other IO thread consumers respond to it.
 624   network_change_observer_.reset(
 625       new LoggingNetworkChangeObserver(net_log_));
 626
 627   // Setup the HistogramWatcher to run on the IO thread.
 628   net::NetworkChangeNotifier::InitHistogramWatcher();
 629
 630 #if defined(ENABLE_EXTENSIONS)
 631   globals_->extension_event_router_forwarder =
 632       extension_event_router_forwarder_;
 633 #endif
 634
 635   // TODO(erikchen): Remove ScopedTracker below once http://crbug.com/466432
 636   // is fixed.
 637   tracked_objects::ScopedTracker tracking_profile3(
 638       FROM_HERE_WITH_EXPLICIT_FUNCTION(
 639           "466432 IOThread::InitAsync::ChromeNetworkDelegate"));
 640   scoped_ptr<ChromeNetworkDelegate> chrome_network_delegate(
 641       new ChromeNetworkDelegate(extension_event_router_forwarder(),
 642                                 &system_enable_referrers_));
 643
 644   // TODO(erikchen): Remove ScopedTracker below once http://crbug.com/466432
 645   // is fixed.
 646   tracked_objects::ScopedTracker tracking_profile4(
 647       FROM_HERE_WITH_EXPLICIT_FUNCTION(
 648           "466432 IOThread::InitAsync::CreateGlobalHostResolver"));
 649   globals_->system_network_delegate = chrome_network_delegate.Pass();
 650   globals_->host_resolver = CreateGlobalHostResolver(net_log_);
 651
 652   std::map<std::string, std::string> network_quality_estimator_params;
 653   variations::GetVariationParams(kNetworkQualityEstimatorFieldTrialName,
 654                                  &network_quality_estimator_params);
 655   globals_->network_quality_estimator.reset(
 656       new net::NetworkQualityEstimator(network_quality_estimator_params));
 657
 658   // TODO(erikchen): Remove ScopedTracker below once http://crbug.com/466432
 659   // is fixed.
 660   tracked_objects::ScopedTracker tracking_profile5(
 661       FROM_HERE_WITH_EXPLICIT_FUNCTION(
 662           "466432 IOThread::InitAsync::UpdateDnsClientEnabled::Start"));
 663   UpdateDnsClientEnabled();
 664   // TODO(erikchen): Remove ScopedTracker below once http://crbug.com/466432
 665   // is fixed.
 666   tracked_objects::ScopedTracker tracking_profile6(
 667       FROM_HERE_WITH_EXPLICIT_FUNCTION(
 668           "466432 IOThread::InitAsync::UpdateDnsClientEnabled::End"));
 669 #if defined(OS_CHROMEOS)
 670   // Creates a CertVerifyProc that doesn't allow any profile-provided certs.
 671   globals_->cert_verifier.reset(new net::MultiThreadedCertVerifier(
 672       new chromeos::CertVerifyProcChromeOS()));
 673 #else
 674   globals_->cert_verifier.reset(new net::MultiThreadedCertVerifier(
 675       net::CertVerifyProc::CreateDefault()));
 676 #endif
 677
 678   globals_->transport_security_state.reset(new net::TransportSecurityState());
 679
 680   // TODO(erikchen): Remove ScopedTracker below once http://crbug.com/466432
 681   // is fixed.
 682   tracked_objects::ScopedTracker tracking_profile8(
 683       FROM_HERE_WITH_EXPLICIT_FUNCTION(
 684           "466432 IOThread::InitAsync::CreateLogVerifiers::Start"));
 685   std::vector<scoped_refptr<net::CTLogVerifier>> ct_logs(
 686       net::ct::CreateLogVerifiersForKnownLogs());
 687
 688   // Add logs from command line
 689   if (command_line.HasSwitch(switches::kCertificateTransparencyLog)) {
 690     std::string switch_value = command_line.GetSwitchValueASCII(
 691         switches::kCertificateTransparencyLog);
 692     for (const base::StringPiece& curr_log : base::SplitStringPiece(
 693              switch_value, ",", base::TRIM_WHITESPACE, base::SPLIT_WANT_ALL)) {
 694       std::vector<std::string> log_metadata = base::SplitString(
 695           curr_log, ":", base::TRIM_WHITESPACE, base::SPLIT_WANT_ALL);
 696       CHECK_GE(log_metadata.size(), 3u)
 697           << "CT log metadata missing: Switch format is "
 698           << "'description:base64_key:url_without_schema'.";
 699       std::string log_description(log_metadata[0]);
 700       std::string log_url(std::string("https://") + log_metadata[2]);
 701       std::string ct_public_key_data;
 702       CHECK(base::Base64Decode(log_metadata[1], &ct_public_key_data))
 703           << "Unable to decode CT public key.";
 704       scoped_refptr<net::CTLogVerifier> external_log_verifier(
 705           net::CTLogVerifier::Create(ct_public_key_data, log_description,
 706                                      log_url));
 707       CHECK(external_log_verifier) << "Unable to parse CT public key.";
 708       VLOG(1) << "Adding log with description " << log_description;
 709       ct_logs.push_back(external_log_verifier);
 710     }
 711   }
 712
 713   // TODO(erikchen): Remove ScopedTracker below once http://crbug.com/466432
 714   // is fixed.
 715   tracked_objects::ScopedTracker tracking_profile9(
 716       FROM_HERE_WITH_EXPLICIT_FUNCTION(
 717           "466432 IOThread::InitAsync::CreateLogVerifiers::End"));
 718   // TODO(erikchen): Remove ScopedTracker below once http://crbug.com/466432
 719   // is fixed.
 720   tracked_objects::ScopedTracker tracking_profile7(
 721       FROM_HERE_WITH_EXPLICIT_FUNCTION(
 722           "466432 IOThread::InitAsync::CreateMultiLogVerifier"));
 723   net::MultiLogCTVerifier* ct_verifier = new net::MultiLogCTVerifier();
 724   globals_->cert_transparency_verifier.reset(ct_verifier);
 725   // Add built-in logs
 726   ct_verifier->AddLogs(ct_logs);
 727
 728   // TODO(erikchen): Remove ScopedTracker below once http://crbug.com/466432
 729   // is fixed.
 730   tracked_objects::ScopedTracker tracking_profile10(
 731       FROM_HERE_WITH_EXPLICIT_FUNCTION(
 732           "466432 IOThread::InitAsync::CertPolicyEnforcer"));
 733   net::CertPolicyEnforcer* policy_enforcer = new net::CertPolicyEnforcer;
 734   globals_->cert_policy_enforcer.reset(policy_enforcer);
 735
 736   globals_->ssl_config_service = GetSSLConfigService();
 737
 738   globals_->http_auth_handler_factory.reset(CreateDefaultAuthHandlerFactory(
 739       globals_->host_resolver.get()));
 740   globals_->http_server_properties.reset(new net::HttpServerPropertiesImpl());
 741   // For the ProxyScriptFetcher, we use a direct ProxyService.
 742   globals_->proxy_script_fetcher_proxy_service.reset(
 743       net::ProxyService::CreateDirectWithNetLog(net_log_));
 744   // In-memory cookie store.
 745   // TODO(erikchen): Remove ScopedTracker below once http://crbug.com/466432
 746   // is fixed.
 747   tracked_objects::ScopedTracker tracking_profile11(
 748       FROM_HERE_WITH_EXPLICIT_FUNCTION(
 749           "466432 IOThread::InitAsync::CreateCookieStore::Start"));
 750   globals_->system_cookie_store =
 751         content::CreateCookieStore(content::CookieStoreConfig());
 752   // TODO(erikchen): Remove ScopedTracker below once http://crbug.com/466432
 753   // is fixed.
 754   tracked_objects::ScopedTracker tracking_profile12(
 755       FROM_HERE_WITH_EXPLICIT_FUNCTION(
 756           "466432 IOThread::InitAsync::CreateCookieStore::End"));
 757   // In-memory channel ID store.
 758   globals_->system_channel_id_service.reset(
 759       new net::ChannelIDService(
 760           new net::DefaultChannelIDStore(NULL),
 761           base::WorkerPool::GetTaskRunner(true)));
 762   // TODO(erikchen): Remove ScopedTracker below once http://crbug.com/466432
 763   // is fixed.
 764   tracked_objects::ScopedTracker tracking_profile12_1(
 765       FROM_HERE_WITH_EXPLICIT_FUNCTION(
 766           "466432 IOThread::InitAsync::CreateDnsProbeService"));
 767   globals_->dns_probe_service.reset(new chrome_browser_net::DnsProbeService());
 768   // TODO(erikchen): Remove ScopedTracker below once http://crbug.com/466432
 769   // is fixed.
 770   tracked_objects::ScopedTracker tracking_profile12_2(
 771       FROM_HERE_WITH_EXPLICIT_FUNCTION(
 772           "466432 IOThread::InitAsync::CreateHostMappingRules"));
 773   globals_->host_mapping_rules.reset(new net::HostMappingRules());
 774   // TODO(erikchen): Remove ScopedTracker below once http://crbug.com/466432
 775   // is fixed.
 776   tracked_objects::ScopedTracker tracking_profile12_3(
 777       FROM_HERE_WITH_EXPLICIT_FUNCTION(
 778           "466432 IOThread::InitAsync::CreateHTTPUserAgentSettings"));
 779   globals_->http_user_agent_settings.reset(
 780       new net::StaticHttpUserAgentSettings(std::string(), GetUserAgent()));
 781   // TODO(erikchen): Remove ScopedTracker below once http://crbug.com/466432
 782   // is fixed.
 783   tracked_objects::ScopedTracker tracking_profile12_4(
 784       FROM_HERE_WITH_EXPLICIT_FUNCTION(
 785           "466432 IOThread::InitAsync::CommandLineConfiguration"));
 786   if (command_line.HasSwitch(switches::kHostRules)) {
 787     TRACE_EVENT_BEGIN0("startup", "IOThread::InitAsync:SetRulesFromString");
 788     globals_->host_mapping_rules->SetRulesFromString(
 789         command_line.GetSwitchValueASCII(switches::kHostRules));
 790     TRACE_EVENT_END0("startup", "IOThread::InitAsync:SetRulesFromString");
 791   }
 792   if (command_line.HasSwitch(switches::kIgnoreCertificateErrors))
 793     globals_->ignore_certificate_errors = true;
 794   if (command_line.HasSwitch(switches::kTestingFixedHttpPort)) {
 795     globals_->testing_fixed_http_port =
 796         GetSwitchValueAsInt(command_line, switches::kTestingFixedHttpPort);
 797   }
 798   if (command_line.HasSwitch(switches::kTestingFixedHttpsPort)) {
 799     globals_->testing_fixed_https_port =
 800         GetSwitchValueAsInt(command_line, switches::kTestingFixedHttpsPort);
 801   }
 802   // TODO(erikchen): Remove ScopedTracker below once http://crbug.com/466432
 803   // is fixed.
 804   tracked_objects::ScopedTracker tracking_profile12_5(
 805       FROM_HERE_WITH_EXPLICIT_FUNCTION(
 806           "466432 IOThread::InitAsync::QuicConfiguration"));
 807   ConfigureQuic(command_line);
 808   if (command_line.HasSwitch(
 809           switches::kEnableUserAlternateProtocolPorts)) {
 810     globals_->enable_user_alternate_protocol_ports = true;
 811   }
 812   // TODO(erikchen): Remove ScopedTracker below once http://crbug.com/466432
 813   // is fixed.
 814   tracked_objects::ScopedTracker tracking_profile13(
 815       FROM_HERE_WITH_EXPLICIT_FUNCTION(
 816           "466432 IOThread::InitAsync::InitializeNetworkOptions"));
 817   InitializeNetworkOptions(command_line);
 818
 819   net::HttpNetworkSession::Params session_params;
 820   InitializeNetworkSessionParams(&session_params);
 821   session_params.net_log = net_log_;
 822   session_params.proxy_service =
 823       globals_->proxy_script_fetcher_proxy_service.get();
 824
 825   // TODO(erikchen): Remove ScopedTracker below once http://crbug.com/466432
 826   // is fixed.
 827   tracked_objects::ScopedTracker tracking_profile14(
 828       FROM_HERE_WITH_EXPLICIT_FUNCTION(
 829           "466432 IOThread::InitAsync::HttpNetorkSession::Start"));
 830   TRACE_EVENT_BEGIN0("startup", "IOThread::InitAsync:HttpNetworkSession");
 831   scoped_refptr<net::HttpNetworkSession> network_session(
 832       new net::HttpNetworkSession(session_params));
 833   // TODO(erikchen): Remove ScopedTracker below once http://crbug.com/466432
 834   // is fixed.
 835   tracked_objects::ScopedTracker tracking_profile15(
 836       FROM_HERE_WITH_EXPLICIT_FUNCTION(
 837           "466432 IOThread::InitAsync::HttpNetorkSession::End"));
 838   globals_->proxy_script_fetcher_http_transaction_factory
 839       .reset(new net::HttpNetworkLayer(network_session.get()));
 840   TRACE_EVENT_END0("startup", "IOThread::InitAsync:HttpNetworkSession");
 841   scoped_ptr<net::URLRequestJobFactoryImpl> job_factory(
 842       new net::URLRequestJobFactoryImpl());
 843
 844   // TODO(erikchen): Remove ScopedTracker below once http://crbug.com/466432
 845   // is fixed.
 846   tracked_objects::ScopedTracker tracking_profile16(
 847       FROM_HERE_WITH_EXPLICIT_FUNCTION(
 848           "466432 IOThread::InitAsync::SetProtocolHandler"));
 849   job_factory->SetProtocolHandler(url::kDataScheme,
 850                                   new net::DataProtocolHandler());
 851   job_factory->SetProtocolHandler(
 852       url::kFileScheme,
 853       new net::FileProtocolHandler(
 854           content::BrowserThread::GetBlockingPool()->
 855               GetTaskRunnerWithShutdownBehavior(
 856                   base::SequencedWorkerPool::SKIP_ON_SHUTDOWN)));
 857 #if !defined(DISABLE_FTP_SUPPORT)
 858   globals_->proxy_script_fetcher_ftp_transaction_factory.reset(
 859       new net::FtpNetworkLayer(globals_->host_resolver.get()));
 860   job_factory->SetProtocolHandler(
 861       url::kFtpScheme,
 862       new net::FtpProtocolHandler(
 863           globals_->proxy_script_fetcher_ftp_transaction_factory.get()));
 864 #endif
 865   globals_->proxy_script_fetcher_url_request_job_factory = job_factory.Pass();
 866
 867   globals_->proxy_script_fetcher_context.reset(
 868       ConstructProxyScriptFetcherContext(globals_, net_log_));
 869
 870   const version_info::Channel channel = chrome::GetChannel();
 871   if (channel == version_info::Channel::UNKNOWN ||
 872       channel == version_info::Channel::CANARY ||
 873       channel == version_info::Channel::DEV) {
 874     globals_->url_request_backoff_manager.reset(
 875         new net::URLRequestBackoffManager());
 876   }
 877
 878 #if defined(OS_MACOSX) && !defined(OS_IOS)
 879   // Start observing Keychain events. This needs to be done on the UI thread,
 880   // as Keychain services requires a CFRunLoop.
 881   BrowserThread::PostTask(BrowserThread::UI,
 882                           FROM_HERE,
 883                           base::Bind(&ObserveKeychainEvents));
 884 #endif
 885
 886   // InitSystemRequestContext turns right around and posts a task back
 887   // to the IO thread, so we can't let it run until we know the IO
 888   // thread has started.
 889   //
 890   // Note that since we are at BrowserThread::Init time, the UI thread
 891   // is blocked waiting for the thread to start.  Therefore, posting
 892   // this task to the main thread's message loop here is guaranteed to
 893   // get it onto the message loop while the IOThread object still
 894   // exists.  However, the message might not be processed on the UI
 895   // thread until after IOThread is gone, so use a weak pointer.
 896   BrowserThread::PostTask(BrowserThread::UI,
 897                           FROM_HERE,
 898                           base::Bind(&IOThread::InitSystemRequestContext,
 899                                      weak_factory_.GetWeakPtr()));
 900 }
 901
 902 void IOThread::CleanUp() {
 903   base::debug::LeakTracker<SafeBrowsingURLRequestContext>::CheckForLeaks();
 904
 905 #if defined(USE_NSS_CERTS) || defined(OS_IOS)
 906   net::ShutdownNSSHttpIO();
 907 #endif
 908
 909   system_url_request_context_getter_ = NULL;
 910
 911   // Release objects that the net::URLRequestContext could have been pointing
 912   // to.
 913
 914   // Shutdown the HistogramWatcher on the IO thread.
 915   net::NetworkChangeNotifier::ShutdownHistogramWatcher();
 916
 917   // This must be reset before the ChromeNetLog is destroyed.
 918   network_change_observer_.reset();
 919
 920   system_proxy_config_service_.reset();
 921
 922   delete globals_;
 923   globals_ = NULL;
 924
 925   base::debug::LeakTracker<SystemURLRequestContextGetter>::CheckForLeaks();
 926 }
 927
 928 void IOThread::InitializeNetworkOptions(const base::CommandLine& command_line) {
 929   // Only handle use-spdy command line flags if "spdy.disabled" preference is
 930   // not disabled via policy.
 931   if (is_spdy_disabled_by_policy_) {
 932     base::FieldTrial* trial = base::FieldTrialList::Find(kSpdyFieldTrialName);
 933     if (trial)
 934       trial->Disable();
 935   } else {
 936     std::string group = base::FieldTrialList::FindFullName(kSpdyFieldTrialName);
 937     VariationParameters params;
 938     if (!variations::GetVariationParams(kSpdyFieldTrialName, &params)) {
 939       params.clear();
 940     }
 941     ConfigureSpdyGlobals(command_line, group, params, globals_);
 942   }
 943
 944   ConfigureTCPFastOpen(command_line);
 945
 946   // TODO(rch): Make the client socket factory a per-network session
 947   // instance, constructed from a NetworkSession::Params, to allow us
 948   // to move this option to IOThread::Globals &
 949   // HttpNetworkSession::Params.
 950 }
 951
 952 void IOThread::ConfigureTCPFastOpen(const base::CommandLine& command_line) {
 953   const std::string trial_group =
 954       base::FieldTrialList::FindFullName(kTCPFastOpenFieldTrialName);
 955   if (trial_group == kTCPFastOpenHttpsEnabledGroupName)
 956     globals_->enable_tcp_fast_open_for_ssl.set(true);
 957   bool always_enable_if_supported =
 958       command_line.HasSwitch(switches::kEnableTcpFastOpen);
 959   // Check for OS support of TCP FastOpen, and turn it on for all connections
 960   // if indicated by user.
 961   net::CheckSupportAndMaybeEnableTCPFastOpen(always_enable_if_supported);
 962 }
 963
 964 // static
 965 void IOThread::ConfigureSpdyGlobals(
 966     const base::CommandLine& command_line,
 967     base::StringPiece spdy_trial_group,
 968     const VariationParameters& spdy_trial_params,
 969     IOThread::Globals* globals) {
 970   if (command_line.HasSwitch(switches::kTrustedSpdyProxy)) {
 971     globals->trusted_spdy_proxy.set(
 972         command_line.GetSwitchValueASCII(switches::kTrustedSpdyProxy));
 973   }
 974   if (command_line.HasSwitch(switches::kIgnoreUrlFetcherCertRequests))
 975     net::URLFetcher::SetIgnoreCertificateRequests(true);
 976
 977   if (command_line.HasSwitch(switches::kUseSpdy)) {
 978     std::string spdy_mode =
 979         command_line.GetSwitchValueASCII(switches::kUseSpdy);
 980     ConfigureSpdyGlobalsFromUseSpdyArgument(spdy_mode, globals);
 981     return;
 982   }
 983
 984   globals->next_protos.clear();
 985   globals->next_protos.push_back(net::kProtoHTTP11);
 986   bool enable_quic = false;
 987   globals->enable_quic.CopyToIfSet(&enable_quic);
 988   if (enable_quic) {
 989     globals->next_protos.push_back(net::kProtoQUIC1SPDY3);
 990   }
 991
 992   // No SPDY command-line flags have been specified. Examine trial groups.
 993   if (spdy_trial_group.starts_with(kSpdyFieldTrialHoldbackGroupNamePrefix)) {
 994     net::HttpStreamFactory::set_spdy_enabled(false);
 995     return;
 996   }
 997   if (spdy_trial_group.starts_with(kSpdyFieldTrialSpdy31GroupNamePrefix)) {
 998     globals->next_protos.push_back(net::kProtoSPDY31);
 999     globals->use_alternate_protocols.set(true);
1000     return;
1001   }
1002   if (spdy_trial_group.starts_with(kSpdyFieldTrialSpdy4GroupNamePrefix)) {
1003     globals->next_protos.push_back(net::kProtoSPDY31);
1004     globals->next_protos.push_back(net::kProtoHTTP2_14);
1005     globals->next_protos.push_back(net::kProtoHTTP2);
1006     globals->use_alternate_protocols.set(true);
1007     return;
1008   }
1009   if (spdy_trial_group.starts_with(kSpdyFieldTrialParametrizedPrefix)) {
1010     bool spdy_enabled = false;
1011     if (base::LowerCaseEqualsASCII(
1012             GetVariationParam(spdy_trial_params, "enable_spdy31"), "true")) {
1013       globals->next_protos.push_back(net::kProtoSPDY31);
1014       spdy_enabled = true;
1015     }
1016     if (base::LowerCaseEqualsASCII(
1017             GetVariationParam(spdy_trial_params, "enable_http2_14"), "true")) {
1018       globals->next_protos.push_back(net::kProtoHTTP2_14);
1019       spdy_enabled = true;
1020     }
1021     if (base::LowerCaseEqualsASCII(
1022             GetVariationParam(spdy_trial_params, "enable_http2"), "true")) {
1023       globals->next_protos.push_back(net::kProtoHTTP2);
1024       spdy_enabled = true;
1025     }
1026     // TODO(bnc): HttpStreamFactory::spdy_enabled_ is redundant with
1027     // globals->next_protos, can it be eliminated?
1028     net::HttpStreamFactory::set_spdy_enabled(spdy_enabled);
1029     globals->use_alternate_protocols.set(true);
1030     return;
1031   }
1032
1033   // By default, enable HTTP/2.
1034   globals->next_protos.push_back(net::kProtoSPDY31);
1035   globals->next_protos.push_back(net::kProtoHTTP2_14);
1036   globals->next_protos.push_back(net::kProtoHTTP2);
1037   globals->use_alternate_protocols.set(true);
1038 }
1039
1040 // static
1041 void IOThread::RegisterPrefs(PrefRegistrySimple* registry) {
1042   registry->RegisterStringPref(prefs::kAuthSchemes,
1043                                "basic,digest,ntlm,negotiate");
1044   registry->RegisterBooleanPref(prefs::kDisableAuthNegotiateCnameLookup, false);
1045   registry->RegisterBooleanPref(prefs::kEnableAuthNegotiatePort, false);
1046   registry->RegisterStringPref(prefs::kAuthServerWhitelist, std::string());
1047   registry->RegisterStringPref(prefs::kAuthNegotiateDelegateWhitelist,
1048                                std::string());
1049   registry->RegisterStringPref(prefs::kGSSAPILibraryName, std::string());
1050   registry->RegisterStringPref(prefs::kAuthAndroidNegotiateAccountType,
1051                                std::string());
1052   registry->RegisterStringPref(
1053       data_reduction_proxy::prefs::kDataReductionProxy, std::string());
1054   registry->RegisterBooleanPref(prefs::kEnableReferrers, true);
1055   data_reduction_proxy::RegisterPrefs(registry);
1056   registry->RegisterBooleanPref(prefs::kBuiltInDnsClientEnabled, true);
1057   registry->RegisterBooleanPref(prefs::kQuickCheckEnabled, true);
1058 }
1059
1060 net::HttpAuthHandlerFactory* IOThread::CreateDefaultAuthHandlerFactory(
1061     net::HostResolver* resolver) {
1062   net::HttpAuthFilterWhitelist* auth_filter_default_credentials = NULL;
1063   if (!auth_server_whitelist_.empty()) {
1064     auth_filter_default_credentials =
1065         new net::HttpAuthFilterWhitelist(auth_server_whitelist_);
1066   }
1067   net::HttpAuthFilterWhitelist* auth_filter_delegate = NULL;
1068   if (!auth_delegate_whitelist_.empty()) {
1069     auth_filter_delegate =
1070         new net::HttpAuthFilterWhitelist(auth_delegate_whitelist_);
1071   }
1072   globals_->url_security_manager.reset(
1073       net::URLSecurityManager::Create(auth_filter_default_credentials,
1074                                       auth_filter_delegate));
1075   std::vector<std::string> supported_schemes = base::SplitString(
1076       auth_schemes_, ",", base::TRIM_WHITESPACE, base::SPLIT_WANT_ALL);
1077
1078   scoped_ptr<net::HttpAuthHandlerRegistryFactory> registry_factory(
1079       net::HttpAuthHandlerRegistryFactory::Create(
1080           supported_schemes, globals_->url_security_manager.get(), resolver,
1081           gssapi_library_name_, auth_android_negotiate_account_type_,
1082           negotiate_disable_cname_lookup_, negotiate_enable_port_));
1083   return registry_factory.release();
1084 }
1085
1086 void IOThread::ClearHostCache() {
1087   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
1088
1089   net::HostCache* host_cache = globals_->host_resolver->GetHostCache();
1090   if (host_cache)
1091     host_cache->clear();
1092 }
1093
1094 void IOThread::InitializeNetworkSessionParams(
1095     net::HttpNetworkSession::Params* params) {
1096   InitializeNetworkSessionParamsFromGlobals(*globals_, params);
1097 }
1098
1099 // static
1100 void IOThread::InitializeNetworkSessionParamsFromGlobals(
1101     const IOThread::Globals& globals,
1102     net::HttpNetworkSession::Params* params) {
1103   params->host_resolver = globals.host_resolver.get();
1104   params->cert_verifier = globals.cert_verifier.get();
1105   params->cert_policy_enforcer = globals.cert_policy_enforcer.get();
1106   params->channel_id_service = globals.system_channel_id_service.get();
1107   params->transport_security_state = globals.transport_security_state.get();
1108   params->ssl_config_service = globals.ssl_config_service.get();
1109   params->http_auth_handler_factory = globals.http_auth_handler_factory.get();
1110   params->http_server_properties =
1111       globals.http_server_properties->GetWeakPtr();
1112   params->network_delegate = globals.system_network_delegate.get();
1113   params->host_mapping_rules = globals.host_mapping_rules.get();
1114   params->ignore_certificate_errors = globals.ignore_certificate_errors;
1115   params->testing_fixed_http_port = globals.testing_fixed_http_port;
1116   params->testing_fixed_https_port = globals.testing_fixed_https_port;
1117   globals.enable_tcp_fast_open_for_ssl.CopyToIfSet(
1118       &params->enable_tcp_fast_open_for_ssl);
1119
1120   globals.initial_max_spdy_concurrent_streams.CopyToIfSet(
1121       &params->spdy_initial_max_concurrent_streams);
1122   globals.enable_spdy_compression.CopyToIfSet(
1123       &params->enable_spdy_compression);
1124   globals.enable_spdy_ping_based_connection_checking.CopyToIfSet(
1125       &params->enable_spdy_ping_based_connection_checking);
1126   globals.spdy_default_protocol.CopyToIfSet(
1127       &params->spdy_default_protocol);
1128   params->next_protos = globals.next_protos;
1129   globals.trusted_spdy_proxy.CopyToIfSet(&params->trusted_spdy_proxy);
1130   params->forced_spdy_exclusions = globals.forced_spdy_exclusions;
1131   globals.use_alternate_protocols.CopyToIfSet(
1132       &params->use_alternate_protocols);
1133   globals.alternative_service_probability_threshold.CopyToIfSet(
1134       &params->alternative_service_probability_threshold);
1135
1136   globals.enable_quic.CopyToIfSet(&params->enable_quic);
1137   globals.enable_insecure_quic.CopyToIfSet(&params->enable_insecure_quic);
1138   globals.enable_quic_for_proxies.CopyToIfSet(&params->enable_quic_for_proxies);
1139   globals.quic_always_require_handshake_confirmation.CopyToIfSet(
1140       &params->quic_always_require_handshake_confirmation);
1141   globals.quic_disable_connection_pooling.CopyToIfSet(
1142       &params->quic_disable_connection_pooling);
1143   globals.quic_load_server_info_timeout_srtt_multiplier.CopyToIfSet(
1144       &params->quic_load_server_info_timeout_srtt_multiplier);
1145   globals.quic_enable_connection_racing.CopyToIfSet(
1146       &params->quic_enable_connection_racing);
1147   globals.quic_enable_non_blocking_io.CopyToIfSet(
1148       &params->quic_enable_non_blocking_io);
1149   globals.quic_prefer_aes.CopyToIfSet(&params->quic_prefer_aes);
1150   globals.quic_disable_disk_cache.CopyToIfSet(
1151       &params->quic_disable_disk_cache);
1152   globals.quic_max_number_of_lossy_connections.CopyToIfSet(
1153       &params->quic_max_number_of_lossy_connections);
1154   globals.quic_packet_loss_threshold.CopyToIfSet(
1155       &params->quic_packet_loss_threshold);
1156   globals.quic_socket_receive_buffer_size.CopyToIfSet(
1157       &params->quic_socket_receive_buffer_size);
1158   globals.enable_quic_port_selection.CopyToIfSet(
1159       &params->enable_quic_port_selection);
1160   globals.quic_max_packet_length.CopyToIfSet(&params->quic_max_packet_length);
1161   globals.quic_user_agent_id.CopyToIfSet(&params->quic_user_agent_id);
1162   globals.quic_supported_versions.CopyToIfSet(
1163       &params->quic_supported_versions);
1164   params->quic_connection_options = globals.quic_connection_options;
1165
1166   globals.origin_to_force_quic_on.CopyToIfSet(
1167       &params->origin_to_force_quic_on);
1168   params->enable_user_alternate_protocol_ports =
1169       globals.enable_user_alternate_protocol_ports;
1170 }
1171
1172 base::TimeTicks IOThread::creation_time() const {
1173   return creation_time_;
1174 }
1175
1176 net::SSLConfigService* IOThread::GetSSLConfigService() {
1177   return ssl_config_service_manager_->Get();
1178 }
1179
1180 void IOThread::ChangedToOnTheRecordOnIOThread() {
1181   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
1182
1183   // Clear the host cache to avoid showing entries from the OTR session
1184   // in about:net-internals.
1185   ClearHostCache();
1186 }
1187
1188 void IOThread::InitSystemRequestContext() {
1189   if (system_url_request_context_getter_.get())
1190     return;
1191   // If we're in unit_tests, IOThread may not be run.
1192   if (!BrowserThread::IsMessageLoopValid(BrowserThread::IO))
1193     return;
1194   system_proxy_config_service_.reset(
1195       ProxyServiceFactory::CreateProxyConfigService(
1196           pref_proxy_config_tracker_.get()));
1197   system_url_request_context_getter_ =
1198       new SystemURLRequestContextGetter(this);
1199   // Safe to post an unretained this pointer, since IOThread is
1200   // guaranteed to outlive the IO BrowserThread.
1201   BrowserThread::PostTask(
1202       BrowserThread::IO,
1203       FROM_HERE,
1204       base::Bind(&IOThread::InitSystemRequestContextOnIOThread,
1205                  base::Unretained(this)));
1206 }
1207
1208 void IOThread::InitSystemRequestContextOnIOThread() {
1209   DCHECK(BrowserThread::CurrentlyOn(BrowserThread::IO));
1210   DCHECK(!globals_->system_proxy_service.get());
1211   DCHECK(system_proxy_config_service_.get());
1212
1213   const base::CommandLine& command_line =
1214       *base::CommandLine::ForCurrentProcess();
1215   globals_->system_proxy_service.reset(
1216       ProxyServiceFactory::CreateProxyService(
1217           net_log_,
1218           globals_->proxy_script_fetcher_context.get(),
1219           globals_->system_network_delegate.get(),
1220           system_proxy_config_service_.release(),
1221           command_line,
1222           quick_check_enabled_.GetValue()));
1223
1224   net::HttpNetworkSession::Params system_params;
1225   InitializeNetworkSessionParams(&system_params);
1226   system_params.net_log = net_log_;
1227   system_params.proxy_service = globals_->system_proxy_service.get();
1228
1229   globals_->system_http_transaction_factory.reset(
1230       new net::HttpNetworkLayer(
1231           new net::HttpNetworkSession(system_params)));
1232   globals_->system_url_request_job_factory.reset(
1233       new net::URLRequestJobFactoryImpl());
1234   globals_->system_request_context.reset(
1235       ConstructSystemRequestContext(globals_, net_log_));
1236   globals_->system_request_context->set_ssl_config_service(
1237       globals_->ssl_config_service.get());
1238   globals_->system_request_context->set_http_server_properties(
1239       globals_->http_server_properties->GetWeakPtr());
1240 }
1241
1242 void IOThread::UpdateDnsClientEnabled() {
1243   globals()->host_resolver->SetDnsClientEnabled(*dns_client_enabled_);
1244 }
1245
1246 void IOThread::ConfigureQuic(const base::CommandLine& command_line) {
1247   // Always fetch the field trial group to ensure it is reported correctly.
1248   // The command line flags will be associated with a group that is reported
1249   // so long as trial is actually queried.
1250   std::string group =
1251       base::FieldTrialList::FindFullName(kQuicFieldTrialName);
1252   VariationParameters params;
1253   if (!variations::GetVariationParams(kQuicFieldTrialName, &params)) {
1254     params.clear();
1255   }
1256
1257   ConfigureQuicGlobals(command_line, group, params, is_quic_allowed_by_policy_,
1258                        globals_);
1259 }
1260
1261 // static
1262 void IOThread::ConfigureQuicGlobals(
1263     const base::CommandLine& command_line,
1264     base::StringPiece quic_trial_group,
1265     const VariationParameters& quic_trial_params,
1266     bool quic_allowed_by_policy,
1267     IOThread::Globals* globals) {
1268   bool enable_quic = ShouldEnableQuic(command_line, quic_trial_group,
1269                                       quic_allowed_by_policy);
1270   globals->enable_quic.set(enable_quic);
1271   bool enable_quic_for_proxies = ShouldEnableQuicForProxies(
1272       command_line, quic_trial_group, quic_allowed_by_policy);
1273   globals->enable_quic_for_proxies.set(enable_quic_for_proxies);
1274   if (enable_quic) {
1275     globals->enable_insecure_quic.set(
1276         ShouldEnableInsecureQuic(command_line, quic_trial_params));
1277     globals->quic_always_require_handshake_confirmation.set(
1278         ShouldQuicAlwaysRequireHandshakeConfirmation(quic_trial_params));
1279     globals->quic_disable_connection_pooling.set(
1280         ShouldQuicDisableConnectionPooling(quic_trial_params));
1281     int receive_buffer_size = GetQuicSocketReceiveBufferSize(quic_trial_params);
1282     if (receive_buffer_size != 0) {
1283       globals->quic_socket_receive_buffer_size.set(receive_buffer_size);
1284     }
1285     float load_server_info_timeout_srtt_multiplier =
1286         GetQuicLoadServerInfoTimeoutSrttMultiplier(quic_trial_params);
1287     if (load_server_info_timeout_srtt_multiplier != 0) {
1288       globals->quic_load_server_info_timeout_srtt_multiplier.set(
1289           load_server_info_timeout_srtt_multiplier);
1290     }
1291     globals->quic_enable_connection_racing.set(
1292         ShouldQuicEnableConnectionRacing(quic_trial_params));
1293     globals->quic_enable_non_blocking_io.set(
1294         ShouldQuicEnableNonBlockingIO(quic_trial_params));
1295     globals->quic_disable_disk_cache.set(
1296         ShouldQuicDisableDiskCache(quic_trial_params));
1297     globals->quic_prefer_aes.set(
1298         ShouldQuicPreferAes(quic_trial_params));
1299     int max_number_of_lossy_connections = GetQuicMaxNumberOfLossyConnections(
1300         quic_trial_params);
1301     if (max_number_of_lossy_connections != 0) {
1302       globals->quic_max_number_of_lossy_connections.set(
1303           max_number_of_lossy_connections);
1304     }
1305     float packet_loss_threshold = GetQuicPacketLossThreshold(quic_trial_params);
1306     if (packet_loss_threshold != 0)
1307       globals->quic_packet_loss_threshold.set(packet_loss_threshold);
1308     globals->enable_quic_port_selection.set(
1309         ShouldEnableQuicPortSelection(command_line));
1310     globals->quic_connection_options =
1311         GetQuicConnectionOptions(command_line, quic_trial_params);
1312   }
1313
1314   size_t max_packet_length = GetQuicMaxPacketLength(command_line,
1315                                                     quic_trial_params);
1316   if (max_packet_length != 0) {
1317     globals->quic_max_packet_length.set(max_packet_length);
1318   }
1319
1320   std::string quic_user_agent_id = chrome::GetChannelString();
1321   if (!quic_user_agent_id.empty())
1322     quic_user_agent_id.push_back(' ');
1323   quic_user_agent_id.append(
1324       version_info::GetProductNameAndVersionForUserAgent());
1325   quic_user_agent_id.push_back(' ');
1326   quic_user_agent_id.append(content::BuildOSCpuInfo());
1327   globals->quic_user_agent_id.set(quic_user_agent_id);
1328
1329   net::QuicVersion version = GetQuicVersion(command_line, quic_trial_params);
1330   if (version != net::QUIC_VERSION_UNSUPPORTED) {
1331     net::QuicVersionVector supported_versions;
1332     supported_versions.push_back(version);
1333     globals->quic_supported_versions.set(supported_versions);
1334   }
1335
1336   double threshold = GetAlternativeProtocolProbabilityThreshold(
1337       command_line, quic_trial_params);
1338   if (threshold >=0 && threshold <= 1) {
1339     globals->alternative_service_probability_threshold.set(threshold);
1340     globals->http_server_properties->SetAlternativeServiceProbabilityThreshold(
1341         threshold);
1342   }
1343
1344   if (command_line.HasSwitch(switches::kOriginToForceQuicOn)) {
1345     net::HostPortPair quic_origin =
1346         net::HostPortPair::FromString(
1347             command_line.GetSwitchValueASCII(switches::kOriginToForceQuicOn));
1348     if (!quic_origin.IsEmpty()) {
1349       globals->origin_to_force_quic_on.set(quic_origin);
1350     }
1351   }
1352 }
1353
1354 bool IOThread::ShouldEnableQuic(const base::CommandLine& command_line,
1355                                 base::StringPiece quic_trial_group,
1356                                 bool quic_allowed_by_policy) {
1357   if (command_line.HasSwitch(switches::kDisableQuic) || !quic_allowed_by_policy)
1358     return false;
1359
1360   if (command_line.HasSwitch(switches::kEnableQuic))
1361     return true;
1362
1363   return quic_trial_group.starts_with(kQuicFieldTrialEnabledGroupName) ||
1364       quic_trial_group.starts_with(kQuicFieldTrialHttpsEnabledGroupName);
1365 }
1366
1367 // static
1368 bool IOThread::ShouldEnableQuicForProxies(const base::CommandLine& command_line,
1369                                           base::StringPiece quic_trial_group,
1370                                           bool quic_allowed_by_policy) {
1371   return ShouldEnableQuic(
1372       command_line, quic_trial_group, quic_allowed_by_policy) ||
1373       ShouldEnableQuicForDataReductionProxy();
1374 }
1375
1376 // static
1377 bool IOThread::ShouldEnableQuicForDataReductionProxy() {
1378   const base::CommandLine& command_line =
1379         *base::CommandLine::ForCurrentProcess();
1380
1381   if (command_line.HasSwitch(switches::kDisableQuic))
1382     return false;
1383
1384   return data_reduction_proxy::params::IsIncludedInQuicFieldTrial();
1385 }
1386
1387 // static
1388 bool IOThread::ShouldEnableInsecureQuic(
1389     const base::CommandLine& command_line,
1390     const VariationParameters& quic_trial_params) {
1391   if (command_line.HasSwitch(switches::kEnableInsecureQuic))
1392     return true;
1393
1394   return base::LowerCaseEqualsASCII(
1395       GetVariationParam(quic_trial_params, "enable_insecure_quic"),
1396       "true");
1397 }
1398
1399 bool IOThread::ShouldEnableQuicPortSelection(
1400     const base::CommandLine& command_line) {
1401   if (command_line.HasSwitch(switches::kDisableQuicPortSelection))
1402     return false;
1403
1404   if (command_line.HasSwitch(switches::kEnableQuicPortSelection))
1405     return true;
1406
1407   return false;  // Default to disabling port selection on all channels.
1408 }
1409
1410 net::QuicTagVector IOThread::GetQuicConnectionOptions(
1411     const base::CommandLine& command_line,
1412     const VariationParameters& quic_trial_params) {
1413   if (command_line.HasSwitch(switches::kQuicConnectionOptions)) {
1414     return net::QuicUtils::ParseQuicConnectionOptions(
1415         command_line.GetSwitchValueASCII(switches::kQuicConnectionOptions));
1416   }
1417
1418   VariationParameters::const_iterator it =
1419       quic_trial_params.find("connection_options");
1420   if (it == quic_trial_params.end()) {
1421     return net::QuicTagVector();
1422   }
1423
1424   return net::QuicUtils::ParseQuicConnectionOptions(it->second);
1425 }
1426
1427 // static
1428 double IOThread::GetAlternativeProtocolProbabilityThreshold(
1429     const base::CommandLine& command_line,
1430     const VariationParameters& quic_trial_params) {
1431   double value;
1432   if (command_line.HasSwitch(
1433           switches::kAlternativeServiceProbabilityThreshold)) {
1434     if (base::StringToDouble(
1435             command_line.GetSwitchValueASCII(
1436                 switches::kAlternativeServiceProbabilityThreshold),
1437             &value)) {
1438       return value;
1439     }
1440   }
1441   if (command_line.HasSwitch(switches::kEnableQuic)) {
1442     return 0;
1443   }
1444   // TODO(bnc): Remove when new parameter name rolls out and server
1445   // configuration is changed.
1446   if (base::StringToDouble(
1447           GetVariationParam(quic_trial_params,
1448                             "alternate_protocol_probability_threshold"),
1449           &value)) {
1450     return value;
1451   }
1452   if (base::StringToDouble(
1453           GetVariationParam(quic_trial_params,
1454                             "alternative_service_probability_threshold"),
1455           &value)) {
1456     return value;
1457   }
1458   return -1;
1459 }
1460
1461 // static
1462 bool IOThread::ShouldQuicAlwaysRequireHandshakeConfirmation(
1463     const VariationParameters& quic_trial_params) {
1464   return base::LowerCaseEqualsASCII(
1465       GetVariationParam(quic_trial_params,
1466                         "always_require_handshake_confirmation"),
1467       "true");
1468 }
1469
1470 // static
1471 bool IOThread::ShouldQuicDisableConnectionPooling(
1472     const VariationParameters& quic_trial_params) {
1473   return base::LowerCaseEqualsASCII(
1474       GetVariationParam(quic_trial_params, "disable_connection_pooling"),
1475       "true");
1476 }
1477
1478 // static
1479 float IOThread::GetQuicLoadServerInfoTimeoutSrttMultiplier(
1480     const VariationParameters& quic_trial_params) {
1481   double value;
1482   if (base::StringToDouble(GetVariationParam(quic_trial_params,
1483                                              "load_server_info_time_to_srtt"),
1484                            &value)) {
1485     return (float)value;
1486   }
1487   return 0.0f;
1488 }
1489
1490 // static
1491 bool IOThread::ShouldQuicEnableConnectionRacing(
1492     const VariationParameters& quic_trial_params) {
1493   return base::LowerCaseEqualsASCII(
1494       GetVariationParam(quic_trial_params, "enable_connection_racing"),
1495       "true");
1496 }
1497
1498 // static
1499 bool IOThread::ShouldQuicEnableNonBlockingIO(
1500     const VariationParameters& quic_trial_params) {
1501   return base::LowerCaseEqualsASCII(
1502       GetVariationParam(quic_trial_params, "enable_non_blocking_io"),
1503       "true");
1504 }
1505
1506 // static
1507 bool IOThread::ShouldQuicDisableDiskCache(
1508     const VariationParameters& quic_trial_params) {
1509   return base::LowerCaseEqualsASCII(
1510       GetVariationParam(quic_trial_params, "disable_disk_cache"), "true");
1511 }
1512
1513 // static
1514 bool IOThread::ShouldQuicPreferAes(
1515     const VariationParameters& quic_trial_params) {
1516   return base::LowerCaseEqualsASCII(
1517       GetVariationParam(quic_trial_params, "prefer_aes"), "true");
1518 }
1519
1520 // static
1521 int IOThread::GetQuicMaxNumberOfLossyConnections(
1522     const VariationParameters& quic_trial_params) {
1523   int value;
1524   if (base::StringToInt(GetVariationParam(quic_trial_params,
1525                                           "max_number_of_lossy_connections"),
1526                         &value)) {
1527     return value;
1528   }
1529   return 0;
1530 }
1531
1532 // static
1533 float IOThread::GetQuicPacketLossThreshold(
1534     const VariationParameters& quic_trial_params) {
1535   double value;
1536   if (base::StringToDouble(GetVariationParam(quic_trial_params,
1537                                              "packet_loss_threshold"),
1538                            &value)) {
1539     return (float)value;
1540   }
1541   return 0.0f;
1542 }
1543
1544 // static
1545 int IOThread::GetQuicSocketReceiveBufferSize(
1546     const VariationParameters& quic_trial_params) {
1547   int value;
1548   if (base::StringToInt(GetVariationParam(quic_trial_params,
1549                                           "receive_buffer_size"),
1550                         &value)) {
1551     return value;
1552   }
1553   return 0;
1554 }
1555
1556 // static
1557 size_t IOThread::GetQuicMaxPacketLength(
1558     const base::CommandLine& command_line,
1559     const VariationParameters& quic_trial_params) {
1560   if (command_line.HasSwitch(switches::kQuicMaxPacketLength)) {
1561     unsigned value;
1562     if (!base::StringToUint(
1563             command_line.GetSwitchValueASCII(switches::kQuicMaxPacketLength),
1564             &value)) {
1565       return 0;
1566     }
1567     return value;
1568   }
1569
1570   unsigned value;
1571   if (base::StringToUint(GetVariationParam(quic_trial_params,
1572                                            "max_packet_length"),
1573                          &value)) {
1574     return value;
1575   }
1576   return 0;
1577 }
1578
1579 // static
1580 net::QuicVersion IOThread::GetQuicVersion(
1581     const base::CommandLine& command_line,
1582     const VariationParameters& quic_trial_params) {
1583   if (command_line.HasSwitch(switches::kQuicVersion)) {
1584     return ParseQuicVersion(
1585         command_line.GetSwitchValueASCII(switches::kQuicVersion));
1586   }
1587
1588   return ParseQuicVersion(GetVariationParam(quic_trial_params, "quic_version"));
1589 }
1590
1591 // static
1592 net::QuicVersion IOThread::ParseQuicVersion(const std::string& quic_version) {
1593   net::QuicVersionVector supported_versions = net::QuicSupportedVersions();
1594   for (size_t i = 0; i < supported_versions.size(); ++i) {
1595     net::QuicVersion version = supported_versions[i];
1596     if (net::QuicVersionToString(version) == quic_version) {
1597       return version;
1598     }
1599   }
1600
1601   return net::QUIC_VERSION_UNSUPPORTED;
1602 }