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