Initialize ios/web_view translate with a system-wide URLRequestContext.

ios/web_view/internal/app/web_view_io_thread.mm

+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "ios/web_view/internal/app/web_view_io_thread.h"
+
+#include <stddef.h>
+
+#include <utility>
+#include <vector>
+
+#include "base/bind.h"
+#include "base/bind_helpers.h"
+#include "base/compiler_specific.h"
+#include "base/debug/leak_tracker.h"
+#include "base/environment.h"
+#include "base/logging.h"
+#include "base/macros.h"
+#include "base/memory/ptr_util.h"
+#include "base/metrics/field_trial.h"
+#include "base/stl_util.h"
+#include "base/strings/string_number_conversions.h"
+#include "base/strings/string_split.h"
+#include "base/strings/string_util.h"
+#include "base/threading/sequenced_worker_pool.h"
+#include "base/threading/thread.h"
+#include "base/time/time.h"
+#include "base/trace_event/trace_event.h"
+#include "components/net_log/chrome_net_log.h"
+#include "components/network_session_configurator/network_session_configurator.h"
+#include "components/prefs/pref_service.h"
+#include "components/proxy_config/ios/proxy_service_factory.h"
+#include "components/proxy_config/pref_proxy_config_tracker.h"
+#include "components/variations/variations_associated_data.h"
+#include "components/version_info/version_info.h"
+#include "ios/web/public/user_agent.h"
+#include "ios/web/public/web_client.h"
+#include "ios/web/public/web_thread.h"
+#include "ios/web_view/internal/web_view_network_delegate.h"
+#include "net/base/sdch_manager.h"
+#include "net/cert/cert_verifier.h"
+#include "net/cert/ct_known_logs.h"
+#include "net/cert/ct_log_verifier.h"
+#include "net/cert/ct_policy_enforcer.h"
+#include "net/cert/ct_verifier.h"
+#include "net/cert/multi_log_ct_verifier.h"
+#include "net/cert/multi_threaded_cert_verifier.h"
+#include "net/cookies/cookie_monster.h"
+#include "net/cookies/cookie_store.h"
+#include "net/dns/host_cache.h"
+#include "net/dns/host_resolver.h"
+#include "net/http/http_auth_filter.h"
+#include "net/http/http_auth_handler_factory.h"
+#include "net/http/http_auth_preferences.h"
+#include "net/http/http_network_layer.h"
+#include "net/http/http_server_properties_impl.h"
+#include "net/log/net_log_event_type.h"
+#include "net/nqe/external_estimate_provider.h"
+#include "net/nqe/network_quality_estimator.h"
+#include "net/proxy/proxy_config_service.h"
+#include "net/proxy/proxy_script_fetcher_impl.h"
+#include "net/proxy/proxy_service.h"
+#include "net/socket/tcp_client_socket.h"
+#include "net/spdy/chromium/spdy_session.h"
+#include "net/ssl/channel_id_service.h"
+#include "net/ssl/default_channel_id_store.h"
+#include "net/url_request/data_protocol_handler.h"
+#include "net/url_request/file_protocol_handler.h"
+#include "net/url_request/static_http_user_agent_settings.h"
+#include "net/url_request/url_request_context.h"
+#include "net/url_request/url_request_context_builder.h"
+#include "net/url_request/url_request_context_getter.h"
+#include "net/url_request/url_request_job_factory_impl.h"
+#include "url/url_constants.h"
+
+#if !defined(__has_feature) || !__has_feature(objc_arc)
+#error "This file requires ARC support."
+#endif
+
+// The WebViewIOThread object must outlive any tasks posted to the IO thread
+// before the Quit task, so base::Bind() calls are not refcounted.
+
+namespace {
+
+const char kSupportedAuthSchemes[] = "basic,digest,ntlm";
+
+// Field trial for network quality estimator. Seeds RTT and downstream
+// throughput observations with values that correspond to the connection type
+// determined by the operating system.
+const char kNetworkQualityEstimatorFieldTrialName[] = "NetworkQualityEstimator";
+
+// Used for the "system" URLRequestContext.
+class SystemURLRequestContext : public net::URLRequestContext {
+ public:
+  SystemURLRequestContext() = default;
+
+ private:
+  ~SystemURLRequestContext() override { AssertNoURLRequests(); }
+};
+
+std::unique_ptr<net::HostResolver> CreateGlobalHostResolver(
+    net::NetLog* net_log) {
+  TRACE_EVENT0("startup", "WebViewIOThread::CreateGlobalHostResolver");
+
+  std::unique_ptr<net::HostResolver> global_host_resolver =
+      net::HostResolver::CreateSystemResolver(net::HostResolver::Options(),
+                                              net_log);
+
+  return global_host_resolver;
+}
+
+}  // namespace
+
+class WebViewIOThread::LoggingNetworkChangeObserver
+    : public net::NetworkChangeNotifier::IPAddressObserver,
+      public net::NetworkChangeNotifier::ConnectionTypeObserver,
+      public net::NetworkChangeNotifier::NetworkChangeObserver {
+ public:
+  // |net_log| must remain valid throughout our lifetime.
+  explicit LoggingNetworkChangeObserver(net::NetLog* net_log)
+      : net_log_(net_log) {
+    net::NetworkChangeNotifier::AddIPAddressObserver(this);
+    net::NetworkChangeNotifier::AddConnectionTypeObserver(this);
+    net::NetworkChangeNotifier::AddNetworkChangeObserver(this);
+  }
+
+  ~LoggingNetworkChangeObserver() override {
+    net::NetworkChangeNotifier::RemoveIPAddressObserver(this);
+    net::NetworkChangeNotifier::RemoveConnectionTypeObserver(this);
+    net::NetworkChangeNotifier::RemoveNetworkChangeObserver(this);
+  }
+
+  // NetworkChangeNotifier::IPAddressObserver implementation.
+  void OnIPAddressChanged() override {
+    VLOG(1) << "Observed a change to the network IP addresses";
+
+    net_log_->AddGlobalEntry(
+        net::NetLogEventType::NETWORK_IP_ADDRESSES_CHANGED);
+  }
+
+  // NetworkChangeNotifier::ConnectionTypeObserver implementation.
+  void OnConnectionTypeChanged(
+      net::NetworkChangeNotifier::ConnectionType type) override {
+    std::string type_as_string =
+        net::NetworkChangeNotifier::ConnectionTypeToString(type);
+
+    VLOG(1) << "Observed a change to network connectivity state "
+            << type_as_string;
+
+    net_log_->AddGlobalEntry(
+        net::NetLogEventType::NETWORK_CONNECTIVITY_CHANGED,
+        net::NetLog::StringCallback("new_connection_type", &type_as_string));
+  }
+
+  // NetworkChangeNotifier::NetworkChangeObserver implementation.
+  void OnNetworkChanged(
+      net::NetworkChangeNotifier::ConnectionType type) override {
+    std::string type_as_string =
+        net::NetworkChangeNotifier::ConnectionTypeToString(type);
+
+    VLOG(1) << "Observed a network change to state " << type_as_string;
+
+    net_log_->AddGlobalEntry(
+        net::NetLogEventType::NETWORK_CHANGED,
+        net::NetLog::StringCallback("new_connection_type", &type_as_string));
+  }
+
+ private:
+  net::NetLog* net_log_;
+  DISALLOW_COPY_AND_ASSIGN(LoggingNetworkChangeObserver);
+};
+
+class SystemURLRequestContextGetter : public net::URLRequestContextGetter {
+ public:
+  explicit SystemURLRequestContextGetter(WebViewIOThread* io_thread);
+
+  // Implementation for net::UrlRequestContextGetter.
+  net::URLRequestContext* GetURLRequestContext() override;
+  scoped_refptr<base::SingleThreadTaskRunner> GetNetworkTaskRunner()
+      const override;
+
+  // Tells the getter that the URLRequestContext is about to be shut down.
+  void Shutdown();
+
+ protected:
+  ~SystemURLRequestContextGetter() override;
+
+ private:
+  WebViewIOThread* io_thread_;  // Weak pointer, owned by ApplicationContext.
+  scoped_refptr<base::SingleThreadTaskRunner> network_task_runner_;
+
+  base::debug::LeakTracker<SystemURLRequestContextGetter> leak_tracker_;
+};
+
+SystemURLRequestContextGetter::SystemURLRequestContextGetter(
+    WebViewIOThread* io_thread)
+    : io_thread_(io_thread),
+      network_task_runner_(
+          web::WebThread::GetTaskRunnerForThread(web::WebThread::IO)) {}
+
+SystemURLRequestContextGetter::~SystemURLRequestContextGetter() {}
+
+net::URLRequestContext* SystemURLRequestContextGetter::GetURLRequestContext() {
+  DCHECK_CURRENTLY_ON(web::WebThread::IO);
+  if (!io_thread_)
+    return nullptr;
+  DCHECK(io_thread_->globals()->system_request_context.get());
+
+  return io_thread_->globals()->system_request_context.get();
+}
+
+scoped_refptr<base::SingleThreadTaskRunner>
+SystemURLRequestContextGetter::GetNetworkTaskRunner() const {
+  return network_task_runner_;
+}
+
+void SystemURLRequestContextGetter::Shutdown() {
+  DCHECK_CURRENTLY_ON(web::WebThread::IO);
+  io_thread_ = nullptr;
+  NotifyContextShuttingDown();
+}
+
+WebViewIOThread::Globals::SystemRequestContextLeakChecker::
+    SystemRequestContextLeakChecker(Globals* globals)
+    : globals_(globals) {
+  DCHECK(globals_);
+}
+
+WebViewIOThread::Globals::SystemRequestContextLeakChecker::
+    ~SystemRequestContextLeakChecker() {
+  if (globals_->system_request_context.get())
+    globals_->system_request_context->AssertNoURLRequests();
+}
+
+WebViewIOThread::Globals::Globals()
+    : system_request_context_leak_checker(this) {}
+
+WebViewIOThread::Globals::~Globals() {}
+
+// |local_state| is passed in explicitly in order to (1) reduce implicit
+// dependencies and (2) make WebViewIOThread more flexible for testing.
+WebViewIOThread::WebViewIOThread(PrefService* local_state,
+                                 net_log::ChromeNetLog* net_log)
+    : net_log_(net_log),
+      globals_(nullptr),
+      creation_time_(base::TimeTicks::Now()),
+      weak_factory_(this) {
+  pref_proxy_config_tracker_ =
+      ProxyServiceFactory::CreatePrefProxyConfigTrackerOfLocalState(
+          local_state);
+  ssl_config_service_manager_.reset(
+      ssl_config::SSLConfigServiceManager::CreateDefaultManager(
+          local_state,
+          web::WebThread::GetTaskRunnerForThread(web::WebThread::IO)));
+
+  web::WebThread::SetDelegate(web::WebThread::IO, this);
+}
+
+WebViewIOThread::~WebViewIOThread() {
+  // This isn't needed for production code, but in tests, WebViewIOThread may
+  // be multiply constructed.
+  web::WebThread::SetDelegate(web::WebThread::IO, nullptr);
+
+  pref_proxy_config_tracker_->DetachFromPrefService();
+  DCHECK(!globals_);
+}
+
+WebViewIOThread::Globals* WebViewIOThread::globals() {
+  DCHECK_CURRENTLY_ON(web::WebThread::IO);
+  return globals_;
+}
+
+void WebViewIOThread::SetGlobalsForTesting(Globals* globals) {
+  DCHECK_CURRENTLY_ON(web::WebThread::IO);
+  DCHECK(!globals || !globals_);
+  globals_ = globals;
+}
+
+net_log::ChromeNetLog* WebViewIOThread::net_log() {
+  return net_log_;
+}
+
+void WebViewIOThread::ChangedToOnTheRecord() {
+  DCHECK_CURRENTLY_ON(web::WebThread::UI);
+  web::WebThread::PostTask(
+      web::WebThread::IO, FROM_HERE,
+      base::Bind(&WebViewIOThread::ChangedToOnTheRecordOnIOThread,
+                 base::Unretained(this)));
+}
+
+net::URLRequestContextGetter*
+WebViewIOThread::system_url_request_context_getter() {
+  DCHECK_CURRENTLY_ON(web::WebThread::UI);
+  if (!system_url_request_context_getter_.get()) {
+    InitSystemRequestContext();
+  }
+  return system_url_request_context_getter_.get();
+}
+
+void WebViewIOThread::Init() {
+  TRACE_EVENT0("startup", "WebViewIOThread::Init");
+  DCHECK_CURRENTLY_ON(web::WebThread::IO);
+
+  DCHECK(!globals_);
+  globals_ = new Globals;
+
+  // Add an observer that will emit network change events to the ChromeNetLog.
+  // Assuming NetworkChangeNotifier dispatches in FIFO order, we should be
+  // logging the network change before other IO thread consumers respond to it.
+  network_change_observer_.reset(new LoggingNetworkChangeObserver(net_log_));
+
+  // Setup the HistogramWatcher to run on the IO thread.
+  net::NetworkChangeNotifier::InitHistogramWatcher();
+
+  std::unique_ptr<ios_web_view::WebViewNetworkDelegate> chrome_network_delegate(
+      new ios_web_view::WebViewNetworkDelegate());
+
+  globals_->system_network_delegate = std::move(chrome_network_delegate);
+  globals_->host_resolver = CreateGlobalHostResolver(net_log_);
+
+  std::map<std::string, std::string> network_quality_estimator_params;
+  variations::GetVariationParams(kNetworkQualityEstimatorFieldTrialName,
+                                 &network_quality_estimator_params);
+
+  std::unique_ptr<net::ExternalEstimateProvider> external_estimate_provider;
+  // Pass ownership.
+  globals_->network_quality_estimator.reset(new net::NetworkQualityEstimator(
+      std::move(external_estimate_provider), network_quality_estimator_params,
+      net_log_));
+
+  globals_->cert_verifier = net::CertVerifier::CreateDefault();
+
+  globals_->transport_security_state.reset(new net::TransportSecurityState());
+
+  std::vector<scoped_refptr<const net::CTLogVerifier>> ct_logs(
+      net::ct::CreateLogVerifiersForKnownLogs());
+
+  net::MultiLogCTVerifier* ct_verifier = new net::MultiLogCTVerifier();
+  globals_->cert_transparency_verifier.reset(ct_verifier);
+  // Add built-in logs
+  ct_verifier->AddLogs(ct_logs);
+
+  globals_->ct_policy_enforcer.reset(new net::CTPolicyEnforcer());
+
+  globals_->ssl_config_service = GetSSLConfigService();
+
+  CreateDefaultAuthHandlerFactory();
+  globals_->http_server_properties.reset(new net::HttpServerPropertiesImpl());
+  // In-memory cookie store.
+  globals_->system_cookie_store.reset(new net::CookieMonster(nullptr, nullptr));
+  // In-memory channel ID store.
+  globals_->system_channel_id_service.reset(
+      new net::ChannelIDService(new net::DefaultChannelIDStore(nullptr)));
+  globals_->system_cookie_store->SetChannelIDServiceID(
+      globals_->system_channel_id_service->GetUniqueID());
+  globals_->http_user_agent_settings.reset(new net::StaticHttpUserAgentSettings(
+      std::string(),
+      web::GetWebClient()->GetUserAgent(web::UserAgentType::MOBILE)));
+
+  params_.ignore_certificate_errors = false;
+  params_.enable_user_alternate_protocol_ports = false;
+
+  std::string quic_user_agent_id = std::string();
+  quic_user_agent_id.append(
+      version_info::GetProductNameAndVersionForUserAgent());
+  quic_user_agent_id.push_back(' ');
+  quic_user_agent_id.append(web::BuildOSCpuInfo());
+
+  network_session_configurator::ParseFieldTrials(
+      /*is_quic_force_disabled=*/false,
+      /*is_quic_force_enabled=*/false, quic_user_agent_id, &params_);

[mmenke, 2017/05/22 17:14:58]

I guess this is modelled after IOThread, or the iOS equivalent?  Is this going
to live happily in tandem with ios_chrome_io_thread.mm, or are they both going
to be sticking around for the foreseeable future?

I'm currently working on getting IOThread using URLRequestContextBuilder, which
should (hopefully) make for much cleaner initialization.  Not quite far enough
along for you use it now, unfortunately, but hopefully only a week or two away. 
Up to you if you want to hold off or not.  Not sure how likely I am to update
iOS code when I'm done (Though this call will need to be updated, at least). 
I'm certainly not going to update two iOS IOThread variants.

+
+  // InitSystemRequestContext turns right around and posts a task back
+  // to the IO thread, so we can't let it run until we know the IO
+  // thread has started.
+  //
+  // Note that since we are at WebThread::Init time, the UI thread
+  // is blocked waiting for the thread to start.  Therefore, posting
+  // this task to the main thread's message loop here is guaranteed to
+  // get it onto the message loop while the WebViewIOThread object still
+  // exists.  However, the message might not be processed on the UI
+  // thread until after WebViewIOThread is gone, so use a weak pointer.
+  web::WebThread::PostTask(
+      web::WebThread::UI, FROM_HERE,
+      base::Bind(&WebViewIOThread::InitSystemRequestContext,
+                 weak_factory_.GetWeakPtr()));
+}
+
+void WebViewIOThread::CleanUp() {
+  system_url_request_context_getter_->Shutdown();
+  system_url_request_context_getter_ = nullptr;
+
+  // Release objects that the net::URLRequestContext could have been pointing
+  // to.
+
+  // Shutdown the HistogramWatcher on the IO thread.
+  net::NetworkChangeNotifier::ShutdownHistogramWatcher();
+
+  // This must be reset before the ChromeNetLog is destroyed.
+  network_change_observer_.reset();
+
+  system_proxy_config_service_.reset();
+
+  delete globals_;
+  globals_ = nullptr;
+
+  base::debug::LeakTracker<SystemURLRequestContextGetter>::CheckForLeaks();
+}
+
+void WebViewIOThread::CreateDefaultAuthHandlerFactory() {
+  std::vector<std::string> supported_schemes =
+      base::SplitString(kSupportedAuthSchemes, ",", base::TRIM_WHITESPACE,
+                        base::SPLIT_WANT_NONEMPTY);
+  globals_->http_auth_preferences.reset(
+      new net::HttpAuthPreferences(supported_schemes, std::string()));
+  globals_->http_auth_handler_factory =
+      net::HttpAuthHandlerRegistryFactory::Create(
+          globals_->http_auth_preferences.get(), globals_->host_resolver.get());
+}
+
+void WebViewIOThread::ClearHostCache() {
+  DCHECK_CURRENTLY_ON(web::WebThread::IO);
+
+  net::HostCache* host_cache = globals_->host_resolver->GetHostCache();
+  if (host_cache)
+    host_cache->clear();
+}
+
+const net::HttpNetworkSession::Params& WebViewIOThread::NetworkSessionParams()
+    const {
+  return params_;
+}
+
+base::TimeTicks WebViewIOThread::creation_time() const {
+  return creation_time_;
+}
+
+net::SSLConfigService* WebViewIOThread::GetSSLConfigService() {
+  return ssl_config_service_manager_->Get();
+}
+
+void WebViewIOThread::ChangedToOnTheRecordOnIOThread() {
+  DCHECK_CURRENTLY_ON(web::WebThread::IO);
+
+  // Clear the host cache to avoid showing entries from the OTR session
+  // in about:net-internals.
+  ClearHostCache();
+}
+
+void WebViewIOThread::InitSystemRequestContext() {
+  if (system_url_request_context_getter_.get())
+    return;
+  // If we're in unit_tests, WebViewIOThread may not be run.
+  if (!web::WebThread::IsMessageLoopValid(web::WebThread::IO))
+    return;
+  system_proxy_config_service_ = ProxyServiceFactory::CreateProxyConfigService(
+      pref_proxy_config_tracker_.get());
+
+  system_url_request_context_getter_ = new SystemURLRequestContextGetter(this);
+  // Safe to post an unretained this pointer, since WebViewIOThread is
+  // guaranteed to outlive the IO WebThread.
+  web::WebThread::PostTask(
+      web::WebThread::IO, FROM_HERE,
+      base::Bind(&WebViewIOThread::InitSystemRequestContextOnIOThread,
+                 base::Unretained(this)));
+}
+
+void WebViewIOThread::InitSystemRequestContextOnIOThread() {
+  DCHECK_CURRENTLY_ON(web::WebThread::IO);
+  DCHECK(!globals_->system_proxy_service.get());
+  DCHECK(system_proxy_config_service_.get());
+
+  globals_->system_proxy_service = ProxyServiceFactory::CreateProxyService(
+      net_log_, nullptr, globals_->system_network_delegate.get(),
+      std::move(system_proxy_config_service_), true /* quick_check_enabled */);
+
+  globals_->system_request_context.reset(
+      ConstructSystemRequestContext(globals_, params_, net_log_));
+}
+
+net::URLRequestContext* WebViewIOThread::ConstructSystemRequestContext(
+    WebViewIOThread::Globals* globals,
+    const net::HttpNetworkSession::Params& params,
+    net::NetLog* net_log) {
+  net::URLRequestContext* context = new SystemURLRequestContext;
+  context->set_net_log(net_log);
+  context->set_host_resolver(globals->host_resolver.get());
+  context->set_cert_verifier(globals->cert_verifier.get());
+  context->set_transport_security_state(
+      globals->transport_security_state.get());
+  context->set_cert_transparency_verifier(
+      globals->cert_transparency_verifier.get());
+  context->set_ssl_config_service(globals->ssl_config_service.get());
+  context->set_http_auth_handler_factory(
+      globals->http_auth_handler_factory.get());
+  context->set_proxy_service(globals->system_proxy_service.get());
+  context->set_ct_policy_enforcer(globals->ct_policy_enforcer.get());
+
+  net::URLRequestJobFactoryImpl* system_job_factory =
+      new net::URLRequestJobFactoryImpl();
+  // Data URLs are always loaded through the system request context on iOS
+  // (due to UIWebView limitations).
+  bool set_protocol = system_job_factory->SetProtocolHandler(
+      url::kDataScheme, base::MakeUnique<net::DataProtocolHandler>());
+  DCHECK(set_protocol);
+  globals->system_url_request_job_factory.reset(system_job_factory);
+  context->set_job_factory(globals->system_url_request_job_factory.get());
+
+  context->set_cookie_store(globals->system_cookie_store.get());
+  context->set_channel_id_service(globals->system_channel_id_service.get());
+  context->set_network_delegate(globals->system_network_delegate.get());
+  context->set_http_user_agent_settings(
+      globals->http_user_agent_settings.get());
+  context->set_network_quality_estimator(
+      globals->network_quality_estimator.get());
+
+  context->set_http_server_properties(globals->http_server_properties.get());
+
+  net::HttpNetworkSession::Params system_params(params);
+  net::URLRequestContextBuilder::SetHttpNetworkSessionComponents(
+      context, &system_params);
+
+  globals->system_http_network_session.reset(
+      new net::HttpNetworkSession(system_params));
+  globals->system_http_transaction_factory.reset(
+      new net::HttpNetworkLayer(globals->system_http_network_session.get()));
+  context->set_http_transaction_factory(
+      globals->system_http_transaction_factory.get());
+
+  return context;
+}