net/url_request/url_request_context_builder.cc

// Copyright (c) 2012 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "net/url_request/url_request_context_builder.h"

#include <string>
#include <utility>
#include <vector>

#include "base/compiler_specific.h"
#include "base/logging.h"
#include "base/macros.h"
#include "base/single_thread_task_runner.h"
#include "base/strings/string_util.h"
#include "base/task/post_task.h"
#include "net/base/cache_type.h"
#include "net/base/net_errors.h"
#include "net/base/network_delegate_impl.h"
#include "net/cert/cert_verifier.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/cookies/cookie_monster.h"
#include "net/dns/host_resolver.h"
#include "net/http/http_auth_handler_factory.h"
#include "net/http/http_cache.h"
#include "net/http/http_network_layer.h"
#include "net/http/http_server_properties_impl.h"
#include "net/http/http_server_properties_manager.h"
#include "net/http/transport_security_persister.h"
#include "net/http/transport_security_state.h"
#include "net/log/net_log.h"
#include "net/net_buildflags.h"
#include "net/nqe/network_quality_estimator.h"
#include "net/quic/quic_stream_factory.h"
#include "net/ssl/channel_id_service.h"
#include "net/ssl/default_channel_id_store.h"
#include "net/ssl/ssl_config_service_defaults.h"
#include "net/url_request/data_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_storage.h"
#include "net/url_request/url_request_intercepting_job_factory.h"
#include "net/url_request/url_request_interceptor.h"
#include "net/url_request/url_request_job_factory_impl.h"
#include "net/url_request/url_request_throttler_manager.h"
#include "url/url_constants.h"

#if !BUILDFLAG(DISABLE_FILE_SUPPORT)
#include "net/url_request/file_protocol_handler.h"  // nogncheck
#endif

#if !BUILDFLAG(DISABLE_FTP_SUPPORT)
#include "net/ftp/ftp_network_layer.h"             // nogncheck
#include "net/url_request/ftp_protocol_handler.h"  // nogncheck
#endif

#if BUILDFLAG(ENABLE_REPORTING)
#include "net/network_error_logging/network_error_logging_delegate.h"
#include "net/network_error_logging/network_error_logging_service.h"
#include "net/reporting/json_parser_delegate.h"
#include "net/reporting/reporting_policy.h"
#include "net/reporting/reporting_service.h"
#endif  // BUILDFLAG(ENABLE_REPORTING)

namespace net {

namespace {

class BasicNetworkDelegate : public NetworkDelegateImpl {
 public:
  BasicNetworkDelegate() = default;
  ~BasicNetworkDelegate() override = default;

 private:
  int OnBeforeURLRequest(URLRequest* request,
                         CompletionOnceCallback callback,
                         GURL* new_url) override {
    return OK;
  }

  int OnBeforeStartTransaction(URLRequest* request,
                               CompletionOnceCallback callback,
                               HttpRequestHeaders* headers) override {
    return OK;
  }

  void OnStartTransaction(URLRequest* request,
                          const HttpRequestHeaders& headers) override {}

  int OnHeadersReceived(
      URLRequest* request,
      CompletionOnceCallback callback,
      const HttpResponseHeaders* original_response_headers,
      scoped_refptr<HttpResponseHeaders>* override_response_headers,
      GURL* allowed_unsafe_redirect_url) override {
    return OK;
  }

  void OnBeforeRedirect(URLRequest* request,
                        const GURL& new_location) override {}

  void OnResponseStarted(URLRequest* request, int net_error) override {}

  void OnCompleted(URLRequest* request, bool started, int net_error) override {}

  void OnURLRequestDestroyed(URLRequest* request) override {}

  void OnPACScriptError(int line_number, const base::string16& error) override {
  }

  NetworkDelegate::AuthRequiredResponse OnAuthRequired(
      URLRequest* request,
      const AuthChallengeInfo& auth_info,
      AuthCallback callback,
      AuthCredentials* credentials) override {
    return NetworkDelegate::AUTH_REQUIRED_RESPONSE_NO_ACTION;
  }

  bool OnCanGetCookies(const URLRequest& request,
                       const CookieList& cookie_list,
                       bool allowed_from_caller) override {
    return allowed_from_caller;
  }

  bool OnCanSetCookie(const URLRequest& request,
                      const CanonicalCookie& cookie,
                      CookieOptions* options,
                      bool allowed_from_caller) override {
    return allowed_from_caller;
  }

  bool OnCanAccessFile(const URLRequest& request,
                       const base::FilePath& original_path,
                       const base::FilePath& absolute_path) const override {
    return true;
  }

  DISALLOW_COPY_AND_ASSIGN(BasicNetworkDelegate);
};

// A URLRequestContext subclass that owns most of its components
// via a UrlRequestContextStorage object. When URLRequestContextBuilder::Build()
// is called, ownership of all URLRequestContext components is passed to the
// ContainerURLRequestContext. Since this cancels requests in its destructor,
// it's not safe to subclass this.
class ContainerURLRequestContext final : public URLRequestContext {
 public:
  ContainerURLRequestContext() : storage_(this) {}

  ~ContainerURLRequestContext() override {
#if BUILDFLAG(ENABLE_REPORTING)
    // Destroy the NetworkErrorLoggingService so that destroying the
    // ReportingService (which might abort in-flight URLRequests, generating
    // network errors) won't recursively try to queue more network error
    // reports.
    storage_.set_network_error_logging_service(nullptr);

    // Destroy the ReportingService before the rest of the URLRequestContext, so
    // it cancels any pending requests it may have.
    storage_.set_reporting_service(nullptr);
#endif  // BUILDFLAG(ENABLE_REPORTING)

    // Shut down the ProxyResolutionService, as it may have pending URLRequests
    // using this context. Since this cancels requests, it's not safe to
    // subclass this, as some parts of the URLRequestContext may then be torn
    // down before this cancels the ProxyResolutionService's URLRequests.
    proxy_resolution_service()->OnShutdown();

    AssertNoURLRequests();
  }

  URLRequestContextStorage* storage() {
    return &storage_;
  }
#if !defined(STARBOARD)
  void set_transport_security_persister(
      std::unique_ptr<TransportSecurityPersister>
          transport_security_persister) {
    transport_security_persister_ = std::move(transport_security_persister);
  }
#endif

 private:
  URLRequestContextStorage storage_;
#if !defined(STARBOARD)
  std::unique_ptr<TransportSecurityPersister> transport_security_persister_;
#endif

  DISALLOW_COPY_AND_ASSIGN(ContainerURLRequestContext);
};

}  // namespace

URLRequestContextBuilder::HttpCacheParams::HttpCacheParams()
    : type(IN_MEMORY),
      max_size(0) {}
URLRequestContextBuilder::HttpCacheParams::~HttpCacheParams() = default;

URLRequestContextBuilder::URLRequestContextBuilder()
    : enable_brotli_(false),
      network_quality_estimator_(nullptr),
      data_enabled_(false),
#if !BUILDFLAG(DISABLE_FILE_SUPPORT)
      file_enabled_(false),
#endif
#if !BUILDFLAG(DISABLE_FTP_SUPPORT)
      ftp_enabled_(false),
#endif
      http_cache_enabled_(true),
      throttling_enabled_(false),
      cookie_store_set_by_client_(false),
      net_log_(nullptr),
      shared_host_resolver_(nullptr),
      pac_quick_check_enabled_(true),
      pac_sanitize_url_policy_(ProxyResolutionService::SanitizeUrlPolicy::SAFE),
      shared_proxy_delegate_(nullptr),
      shared_http_auth_handler_factory_(nullptr),
#if BUILDFLAG(ENABLE_REPORTING)
      shared_cert_verifier_(nullptr),
      network_error_logging_enabled_(false) {
#else   // !BUILDFLAG(ENABLE_REPORTING)
      shared_cert_verifier_(nullptr){
#endif  // !BUILDFLAG(ENABLE_REPORTING)
}

URLRequestContextBuilder::~URLRequestContextBuilder() = default;

void URLRequestContextBuilder::SetHttpNetworkSessionComponents(
    const URLRequestContext* request_context,
    HttpNetworkSession::Context* session_context) {
  session_context->host_resolver = request_context->host_resolver();
  session_context->cert_verifier = request_context->cert_verifier();
  session_context->transport_security_state =
      request_context->transport_security_state();
  session_context->cert_transparency_verifier =
      request_context->cert_transparency_verifier();
  session_context->ct_policy_enforcer = request_context->ct_policy_enforcer();
  session_context->proxy_resolution_service =
      request_context->proxy_resolution_service();
  session_context->ssl_config_service = request_context->ssl_config_service();
  session_context->http_auth_handler_factory =
      request_context->http_auth_handler_factory();
  session_context->http_server_properties =
      request_context->http_server_properties();
  session_context->net_log = request_context->net_log();
  session_context->channel_id_service = request_context->channel_id_service();
  session_context->network_quality_provider =
      request_context->network_quality_estimator();
  if (request_context->network_quality_estimator()) {
    session_context->socket_performance_watcher_factory =
        request_context->network_quality_estimator()
            ->GetSocketPerformanceWatcherFactory();
  }
}

void URLRequestContextBuilder::set_accept_language(
    const std::string& accept_language) {
  DCHECK(!http_user_agent_settings_);
  accept_language_ = accept_language;
}
void URLRequestContextBuilder::set_user_agent(const std::string& user_agent) {
  DCHECK(!http_user_agent_settings_);
  user_agent_ = user_agent;
}

void URLRequestContextBuilder::set_http_user_agent_settings(
    std::unique_ptr<HttpUserAgentSettings> http_user_agent_settings) {
  http_user_agent_settings_ = std::move(http_user_agent_settings);
}

void URLRequestContextBuilder::EnableHttpCache(const HttpCacheParams& params) {
  http_cache_enabled_ = true;
  http_cache_params_ = params;
}

void URLRequestContextBuilder::DisableHttpCache() {
  http_cache_enabled_ = false;
  http_cache_params_ = HttpCacheParams();
}

void URLRequestContextBuilder::SetSpdyAndQuicEnabled(bool spdy_enabled,
                                                     bool quic_enabled) {
  http_network_session_params_.enable_http2 = spdy_enabled;
  http_network_session_params_.enable_quic = quic_enabled;
}

void URLRequestContextBuilder::set_ct_verifier(
    std::unique_ptr<CTVerifier> ct_verifier) {
  ct_verifier_ = std::move(ct_verifier);
}

void URLRequestContextBuilder::set_ct_policy_enforcer(
    std::unique_ptr<CTPolicyEnforcer> ct_policy_enforcer) {
  ct_policy_enforcer_ = std::move(ct_policy_enforcer);
}

void URLRequestContextBuilder::SetCertVerifier(
    std::unique_ptr<CertVerifier> cert_verifier) {
  DCHECK(!shared_cert_verifier_);
  cert_verifier_ = std::move(cert_verifier);
}

void URLRequestContextBuilder::SetSharedCertVerifier(
    CertVerifier* shared_cert_verifier) {
  DCHECK(!cert_verifier_);
  shared_cert_verifier_ = shared_cert_verifier;
}

#if BUILDFLAG(ENABLE_REPORTING)
void URLRequestContextBuilder::enable_reporting(
    std::unique_ptr<ReportingPolicy> reporting_policy,
    std::unique_ptr<JSONParserDelegate> json_parser) {
  reporting_policy_ = std::move(reporting_policy);
  json_parser_ = std::move(json_parser);
}

void URLRequestContextBuilder::set_reporting_policy(
    std::unique_ptr<ReportingPolicy> reporting_policy) {
  enable_reporting(std::move(reporting_policy),
                   std::make_unique<InProcessJSONParser>());
}
#endif  // BUILDFLAG(ENABLE_REPORTING)

void URLRequestContextBuilder::SetInterceptors(
    std::vector<std::unique_ptr<URLRequestInterceptor>>
        url_request_interceptors) {
  url_request_interceptors_ = std::move(url_request_interceptors);
}

void URLRequestContextBuilder::set_create_intercepting_job_factory(
    CreateInterceptingJobFactory create_intercepting_job_factory) {
  DCHECK(!create_intercepting_job_factory_);
  create_intercepting_job_factory_ = std::move(create_intercepting_job_factory);
}

void URLRequestContextBuilder::SetCookieAndChannelIdStores(
    std::unique_ptr<CookieStore> cookie_store,
    std::unique_ptr<ChannelIDService> channel_id_service) {
  cookie_store_set_by_client_ = true;
  // If |cookie_store| is NULL, |channel_id_service| must be NULL too.
  DCHECK(cookie_store || !channel_id_service);
  cookie_store_ = std::move(cookie_store);
  channel_id_service_ = std::move(channel_id_service);
}

void URLRequestContextBuilder::SetProtocolHandler(
    const std::string& scheme,
    std::unique_ptr<URLRequestJobFactory::ProtocolHandler> protocol_handler) {
  DCHECK(protocol_handler);
  // If a consumer sets a ProtocolHandler and then overwrites it with another,
  // it's probably a bug.
  DCHECK_EQ(0u, protocol_handlers_.count(scheme));
  protocol_handlers_[scheme] = std::move(protocol_handler);
}

void URLRequestContextBuilder::set_host_resolver(
    std::unique_ptr<HostResolver> host_resolver) {
  DCHECK(!shared_host_resolver_);
  host_resolver_ = std::move(host_resolver);
}

void URLRequestContextBuilder::set_shared_host_resolver(
    HostResolver* shared_host_resolver) {
  DCHECK(!host_resolver_);
  shared_host_resolver_ = shared_host_resolver;
}

void URLRequestContextBuilder::SetCreateLayeredNetworkDelegateCallback(
    CreateLayeredNetworkDelegate create_layered_network_delegate_callback) {
  create_layered_network_delegate_callback_ =
      std::move(create_layered_network_delegate_callback);
}

void URLRequestContextBuilder::set_proxy_delegate(
    std::unique_ptr<ProxyDelegate> proxy_delegate) {
  DCHECK(!shared_proxy_delegate_);
  proxy_delegate_ = std::move(proxy_delegate);
}

void URLRequestContextBuilder::set_shared_proxy_delegate(
    ProxyDelegate* shared_proxy_delegate) {
  DCHECK(!proxy_delegate_);
  shared_proxy_delegate_ = shared_proxy_delegate;
}

void URLRequestContextBuilder::SetHttpAuthHandlerFactory(
    std::unique_ptr<HttpAuthHandlerFactory> factory) {
  DCHECK(!shared_http_auth_handler_factory_);
  http_auth_handler_factory_ = std::move(factory);
}

void URLRequestContextBuilder::set_shared_http_auth_handler_factory(
    HttpAuthHandlerFactory* shared_http_auth_handler_factory) {
  DCHECK(!http_auth_handler_factory_);
  shared_http_auth_handler_factory_ = shared_http_auth_handler_factory;
}

void URLRequestContextBuilder::SetHttpServerProperties(
    std::unique_ptr<HttpServerProperties> http_server_properties) {
  http_server_properties_ = std::move(http_server_properties);
}

void URLRequestContextBuilder::SetCreateHttpTransactionFactoryCallback(
    CreateHttpTransactionFactoryCallback
        create_http_network_transaction_factory) {
  create_http_network_transaction_factory_ =
      std::move(create_http_network_transaction_factory);
}

std::unique_ptr<URLRequestContext> URLRequestContextBuilder::Build() {
  std::unique_ptr<ContainerURLRequestContext> context(
      new ContainerURLRequestContext());
  URLRequestContextStorage* storage = context->storage();

  if (!name_.empty())
    context->set_name(name_);
  context->set_enable_brotli(enable_brotli_);
  context->set_network_quality_estimator(network_quality_estimator_);

  if (http_user_agent_settings_) {
    storage->set_http_user_agent_settings(std::move(http_user_agent_settings_));
  } else {
    storage->set_http_user_agent_settings(
        std::make_unique<StaticHttpUserAgentSettings>(accept_language_,
                                                      user_agent_));
  }

  if (!network_delegate_)
    network_delegate_.reset(new BasicNetworkDelegate);
  if (create_layered_network_delegate_callback_) {
    network_delegate_ = std::move(create_layered_network_delegate_callback_)
                            .Run(std::move(network_delegate_));
  }
  storage->set_network_delegate(std::move(network_delegate_));

  if (net_log_) {
    // Unlike the other builder parameters, |net_log_| is not owned by the
    // builder or resulting context.
    context->set_net_log(net_log_);
  } else {
    storage->set_net_log(std::make_unique<NetLog>());
  }

  if (host_resolver_) {
    DCHECK(!shared_host_resolver_);
    storage->set_host_resolver(std::move(host_resolver_));
  } else if (shared_host_resolver_) {
    context->set_host_resolver(shared_host_resolver_);
  } else {
    storage->set_host_resolver(
        HostResolver::CreateDefaultResolver(context->net_log()));
  }

  if (ssl_config_service_) {
    storage->set_ssl_config_service(std::move(ssl_config_service_));
  } else {
    storage->set_ssl_config_service(
        std::make_unique<SSLConfigServiceDefaults>());
  }

  if (http_auth_handler_factory_) {
    DCHECK(!shared_http_auth_handler_factory_);
    storage->set_http_auth_handler_factory(
        std::move(http_auth_handler_factory_));
  } else if (shared_http_auth_handler_factory_) {
    context->set_http_auth_handler_factory(shared_http_auth_handler_factory_);
  } else {
    storage->set_http_auth_handler_factory(
        HttpAuthHandlerRegistryFactory::CreateDefault(
            context->host_resolver()));
  }

  if (cookie_store_set_by_client_) {
    storage->set_cookie_store(std::move(cookie_store_));
    storage->set_channel_id_service(std::move(channel_id_service_));
  } else {
    std::unique_ptr<CookieStore> cookie_store(
        new CookieMonster(nullptr /* store */, nullptr /* channel_id_service */,
                          context->net_log()));
    std::unique_ptr<ChannelIDService> channel_id_service(
        new ChannelIDService(new DefaultChannelIDStore(NULL)));
    cookie_store->SetChannelIDServiceID(channel_id_service->GetUniqueID());
    storage->set_cookie_store(std::move(cookie_store));
    storage->set_channel_id_service(std::move(channel_id_service));
  }

  storage->set_transport_security_state(
      std::make_unique<TransportSecurityState>());
#if !defined(STARBOARD)
  if (!transport_security_persister_path_.empty()) {
    // Use a low priority because saving this should not block anything
    // user-visible. Block shutdown to ensure it does get persisted to disk,
    // since it contains security-relevant information.
    scoped_refptr<base::SequencedTaskRunner> task_runner(
        base::CreateSequencedTaskRunnerWithTraits(
            {base::MayBlock(), base::TaskPriority::BEST_EFFORT,
             base::TaskShutdownBehavior::BLOCK_SHUTDOWN}));

    context->set_transport_security_persister(
        std::make_unique<TransportSecurityPersister>(
            context->transport_security_state(),
            transport_security_persister_path_, task_runner));
  }
#endif  // !defined(STARBOARD)

  if (http_server_properties_) {
    storage->set_http_server_properties(std::move(http_server_properties_));
  } else {
    storage->set_http_server_properties(
        std::unique_ptr<HttpServerProperties>(new HttpServerPropertiesImpl()));
  }

  if (cert_verifier_) {
    storage->set_cert_verifier(std::move(cert_verifier_));
  } else if (shared_cert_verifier_) {
    context->set_cert_verifier(shared_cert_verifier_);
  } else {
    storage->set_cert_verifier(CertVerifier::CreateDefault());
  }

  if (ct_verifier_) {
    storage->set_cert_transparency_verifier(std::move(ct_verifier_));
  } else {
    storage->set_cert_transparency_verifier(
        std::make_unique<MultiLogCTVerifier>());
  }
  if (ct_policy_enforcer_) {
    storage->set_ct_policy_enforcer(std::move(ct_policy_enforcer_));
  } else {
    storage->set_ct_policy_enforcer(
        std::make_unique<DefaultCTPolicyEnforcer>());
  }

  if (throttling_enabled_) {
    storage->set_throttler_manager(
        std::make_unique<URLRequestThrottlerManager>());
  }

  if (!proxy_resolution_service_) {
#if !defined(OS_LINUX) && !defined(OS_ANDROID)
    // TODO(willchan): Switch to using this code when
    // ProxyResolutionService::CreateSystemProxyConfigService()'s signature
    // doesn't suck.
    if (!proxy_config_service_) {
      proxy_config_service_ =
          ProxyResolutionService::CreateSystemProxyConfigService(
              base::ThreadTaskRunnerHandle::Get().get());
    }
#endif  // !defined(OS_LINUX) && !defined(OS_ANDROID)
    proxy_resolution_service_ = CreateProxyResolutionService(
        std::move(proxy_config_service_), context.get(),
        context->host_resolver(), context->network_delegate(),
        context->net_log());
    proxy_resolution_service_->set_quick_check_enabled(pac_quick_check_enabled_);
    proxy_resolution_service_->set_sanitize_url_policy(pac_sanitize_url_policy_);
  }
  ProxyResolutionService* proxy_resolution_service =
      proxy_resolution_service_.get();
  storage->set_proxy_resolution_service(std::move(proxy_resolution_service_));

  HttpNetworkSession::Context network_session_context;
  SetHttpNetworkSessionComponents(context.get(), &network_session_context);

  if (proxy_delegate_) {
    DCHECK(!shared_proxy_delegate_);
    proxy_resolution_service->AssertNoProxyDelegate();
    proxy_resolution_service->SetProxyDelegate(proxy_delegate_.get());
    storage->set_proxy_delegate(std::move(proxy_delegate_));
  } else if (shared_proxy_delegate_) {
    proxy_resolution_service->AssertNoProxyDelegate();
    proxy_resolution_service->SetProxyDelegate(shared_proxy_delegate_);
  }

  storage->set_http_network_session(std::make_unique<HttpNetworkSession>(
      http_network_session_params_, network_session_context));

  std::unique_ptr<HttpTransactionFactory> http_transaction_factory;
  if (!create_http_network_transaction_factory_.is_null()) {
    http_transaction_factory =
        std::move(create_http_network_transaction_factory_)
            .Run(storage->http_network_session());
  } else {
    http_transaction_factory =
        std::make_unique<HttpNetworkLayer>(storage->http_network_session());
  }

  if (http_cache_enabled_) {
    std::unique_ptr<HttpCache::BackendFactory> http_cache_backend;
    if (http_cache_params_.type != HttpCacheParams::IN_MEMORY) {
      // TODO(mmenke): Maybe merge BackendType and HttpCacheParams::Type? The
      // first doesn't include in memory, so may require some work.
      BackendType backend_type = CACHE_BACKEND_DEFAULT;
      switch (http_cache_params_.type) {
        case HttpCacheParams::DISK:
          backend_type = CACHE_BACKEND_DEFAULT;
          break;
        case HttpCacheParams::DISK_BLOCKFILE:
          backend_type = CACHE_BACKEND_BLOCKFILE;
          break;
        case HttpCacheParams::DISK_SIMPLE:
          backend_type = CACHE_BACKEND_SIMPLE;
          break;
        case HttpCacheParams::IN_MEMORY:
          NOTREACHED();
          break;
      }
      http_cache_backend.reset(new HttpCache::DefaultBackend(
          DISK_CACHE, backend_type, http_cache_params_.path,
          http_cache_params_.max_size));
    } else {
      http_cache_backend =
          HttpCache::DefaultBackend::InMemory(http_cache_params_.max_size);
    }
#if defined(OS_ANDROID)
    http_cache_backend->SetAppStatusListener(
        http_cache_params_.app_status_listener);
#endif

    http_transaction_factory.reset(
        new HttpCache(std::move(http_transaction_factory),
                      std::move(http_cache_backend), true));
  }
  storage->set_http_transaction_factory(std::move(http_transaction_factory));

  URLRequestJobFactoryImpl* job_factory = new URLRequestJobFactoryImpl;
  // Adds caller-provided protocol handlers first so that these handlers are
  // used over data/file/ftp handlers below.
  for (auto& scheme_handler : protocol_handlers_) {
    job_factory->SetProtocolHandler(scheme_handler.first,
                                    std::move(scheme_handler.second));
  }
  protocol_handlers_.clear();

  if (data_enabled_)
    job_factory->SetProtocolHandler(url::kDataScheme,
                                    std::make_unique<DataProtocolHandler>());

#if !BUILDFLAG(DISABLE_FILE_SUPPORT)
  if (file_enabled_) {
    job_factory->SetProtocolHandler(
        url::kFileScheme,
        std::make_unique<FileProtocolHandler>(base::CreateTaskRunnerWithTraits(
            {base::MayBlock(), base::TaskPriority::USER_BLOCKING,
             base::TaskShutdownBehavior::SKIP_ON_SHUTDOWN})));
  }
#endif  // !BUILDFLAG(DISABLE_FILE_SUPPORT)

#if !BUILDFLAG(DISABLE_FTP_SUPPORT)
  if (ftp_enabled_) {
    job_factory->SetProtocolHandler(
        url::kFtpScheme, FtpProtocolHandler::Create(context->host_resolver()));
  }
#endif  // !BUILDFLAG(DISABLE_FTP_SUPPORT)

  std::unique_ptr<URLRequestJobFactory> top_job_factory(job_factory);
  if (!url_request_interceptors_.empty()) {
    // Set up interceptors in the reverse order.

    for (auto i = url_request_interceptors_.rbegin();
         i != url_request_interceptors_.rend(); ++i) {
      top_job_factory.reset(new URLRequestInterceptingJobFactory(
          std::move(top_job_factory), std::move(*i)));
    }
    url_request_interceptors_.clear();
  }
  if (create_intercepting_job_factory_) {
    top_job_factory = std::move(create_intercepting_job_factory_)
                          .Run(std::move(top_job_factory));
  }
  storage->set_job_factory(std::move(top_job_factory));

#if BUILDFLAG(ENABLE_REPORTING)
  // Note: ReportingService::Create and NetworkErrorLoggingService::Create can
  // both return nullptr if the corresponding base::Feature is disabled.

  if (reporting_policy_) {
    storage->set_reporting_service(ReportingService::Create(
        *reporting_policy_, std::move(json_parser_), context.get()));
  }

  if (network_error_logging_enabled_) {
    storage->set_network_error_logging_service(
        NetworkErrorLoggingService::Create(
            NetworkErrorLoggingDelegate::Create()));
  }

  // If both Reporting and Network Error Logging are actually enabled, then
  // connect them so Network Error Logging can use Reporting to deliver error
  // reports.
  if (context->reporting_service() &&
      context->network_error_logging_service()) {
    context->network_error_logging_service()->SetReportingService(
        context->reporting_service());
  }
#endif  // BUILDFLAG(ENABLE_REPORTING)

  return std::move(context);
}

std::unique_ptr<ProxyResolutionService>
URLRequestContextBuilder::CreateProxyResolutionService(
    std::unique_ptr<ProxyConfigService> proxy_config_service,
    URLRequestContext* url_request_context,
    HostResolver* host_resolver,
    NetworkDelegate* network_delegate,
    NetLog* net_log) {
  return ProxyResolutionService::CreateUsingSystemProxyResolver(
      std::move(proxy_config_service), net_log);
}

}  // namespace net