Use TaskRunner passed in to URLRequestContextBuilder only for the cache

net/url_request/url_request_context_builder.h

 // 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.
 
 // This class is useful for building a simple URLRequestContext. Most creators
 // of new URLRequestContexts should use this helper class to construct it. Call
 // any configuration params, and when done, invoke Build() to construct the
 // URLRequestContext. This URLRequestContext will own all its own storage.
 //
 // URLRequestContextBuilder and its associated params classes are initially
@@ skipping 26 matching lines @@
 #include "net/net_features.h"
 #include "net/proxy/proxy_config_service.h"
 #include "net/proxy/proxy_service.h"
 #include "net/quic/core/quic_packets.h"
 #include "net/socket/next_proto.h"
 #include "net/ssl/ssl_config_service.h"
 #include "net/url_request/url_request_job_factory.h"
 
 namespace base {
 class SingleThreadTaskRunner;
-class SequencedTaskRunner;
-class TaskRunner;
 }
 
 namespace net {
 
 class CertVerifier;
 class ChannelIDService;
 class CookieStore;
 class CTPolicyEnforcer;
 class CTVerifier;
 class HttpAuthHandlerFactory;
@@ skipping 216 matching lines @@
   // If |cookie_store| is not NULL and |channel_id_service| is NULL,
   // only ChannelIdService is disabled for this context.
   // Note that a persistent cookie store should not be used with an in-memory
   // channel id service, and one cookie store should not be shared between
   // multiple channel-id stores (or used both with and without a channel id
   // store).
   void SetCookieAndChannelIdStores(
       std::unique_ptr<CookieStore> cookie_store,
       std::unique_ptr<ChannelIDService> channel_id_service);
 
-  // Sets the task runner used to perform file operations. If not set,
-  // TaskSchedulers will be used instead.
-  void SetFileTaskRunner(
-      const scoped_refptr<base::SingleThreadTaskRunner>& task_runner);
+  // Sets the SingleThreadTaskRunner used to perform cache operations. If not
+  // set, one will be created via a TaskScheduler instead. Other file tasks will
+  // use the task scheduler, but the cache needs a SingleThreadTaskRunner, so
+  // best to keep that configurable by the consumer.
+  void SetCacheThreadTaskRunner(
+      scoped_refptr<base::SingleThreadTaskRunner> cache_thread_task_runner);
 
   // Note that if SDCH is enabled without a policy object observing
   // the SDCH manager and handling at least Get-Dictionary events, the
   // result will be "Content-Encoding: sdch" advertisements, but no
   // dictionaries fetches and no specific dictionaries advertised.
   // SdchOwner in net/sdch/sdch_owner.h is a simple policy object.
   void set_sdch_enabled(bool enable) { sdch_enabled_ = enable; }
 
   // Sets a specific HttpServerProperties for use in the
   // URLRequestContext rather than creating a default HttpServerPropertiesImpl.
   void SetHttpServerProperties(
       std::unique_ptr<HttpServerProperties> http_server_properties);
 
   // Creates a mostly self-contained URLRequestContext. May only be called once
   // per URLRequestContextBuilder. After this is called, the Builder can be
   // safely destroyed.
   std::unique_ptr<URLRequestContext> Build();
 
  protected:
   // Lets subclasses override ProxyService creation, using a ProxyService that
   // uses the URLRequestContext itself to get PAC scripts. When this method is
   // invoked, the URLRequestContext is not yet ready to service requests.
   virtual std::unique_ptr<ProxyService> CreateProxyService(
       std::unique_ptr<ProxyConfigService> proxy_config_service,
       URLRequestContext* url_request_context,
       HostResolver* host_resolver,
       NetworkDelegate* network_delegate,
       NetLog* net_log);
 
-  // Returns a TaskRunner with the specified traits. If |file_task_runner_| is
-  // non-NULL, uses that. Otherwise, uses base/task_scheduler/ and the specified
-  // traits.
-  scoped_refptr<base::TaskRunner> GetFileTaskRunner(
-      const base::TaskTraits& traits);
-  scoped_refptr<base::SequencedTaskRunner> GetFileSequencedTaskRunner(
-      const base::TaskTraits& traits);
-  scoped_refptr<base::SingleThreadTaskRunner> GetFileSingleThreadTaskRunner(
-      const base::TaskTraits& traits);
-
  private:
   const char* name_;
   bool enable_brotli_;
   NetworkQualityEstimator* network_quality_estimator_;
 
   std::string accept_language_;
   std::string user_agent_;
   // Include support for data:// requests.
   bool data_enabled_;
 #if !BUILDFLAG(DISABLE_FILE_SUPPORT)
   // Include support for file:// requests.
   bool file_enabled_;
 #endif
 #if !BUILDFLAG(DISABLE_FTP_SUPPORT)
   // Include support for ftp:// requests.
   bool ftp_enabled_;
 #endif
   bool http_cache_enabled_;
   bool throttling_enabled_;
   bool sdch_enabled_;
   bool cookie_store_set_by_client_;
 
-  scoped_refptr<base::SingleThreadTaskRunner> file_task_runner_;
+  scoped_refptr<base::SingleThreadTaskRunner> cache_thread_task_runner_;
   HttpCacheParams http_cache_params_;
   HttpNetworkSession::Params http_network_session_params_;
   base::FilePath transport_security_persister_path_;
   NetLog* net_log_;
   std::unique_ptr<HostResolver> host_resolver_;
   std::unique_ptr<ChannelIDService> channel_id_service_;
   std::unique_ptr<ProxyConfigService> proxy_config_service_;
   bool pac_quick_check_enabled_;
   ProxyService::SanitizeUrlPolicy pac_sanitize_url_policy_;
   std::unique_ptr<ProxyService> proxy_service_;
@@ skipping 12 matching lines @@
   std::unique_ptr<HttpServerProperties> http_server_properties_;
   std::map<std::string, std::unique_ptr<URLRequestJobFactory::ProtocolHandler>>
       protocol_handlers_;
 
   DISALLOW_COPY_AND_ASSIGN(URLRequestContextBuilder);
 };
 
 }  // namespace net
 
 #endif  // NET_URL_REQUEST_URL_REQUEST_CONTEXT_BUILDER_H_