Provide mutable members of UrlRequestContext via pure-virtual interface

chrome/browser/io_thread.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.
 
 #ifndef CHROME_BROWSER_IO_THREAD_H_
 #define CHROME_BROWSER_IO_THREAD_H_
 
 #include <string>
 
 #include "base/basictypes.h"
 #include "base/compiler_specific.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/memory/weak_ptr.h"
 #include "chrome/browser/api/prefs/pref_member.h"
 #include "chrome/browser/net/ssl_config_service_manager.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/browser_thread_delegate.h"
 #include "net/base/network_change_notifier.h"
 
 class ChromeNetLog;
 class PrefProxyConfigTrackerImpl;
 class PrefService;
 class SystemURLRequestContextGetter;
+class BasicHttpUserAgentSettings;
 
 namespace chrome_browser_net {
 class HttpPipeliningCompatibilityClient;
 class LoadTimeStats;
 }
 
 namespace extensions {
 class EventRouterForwarder;
 }
 
@@ skipping 73 matching lines @@
     // |system_cookie_store| and |system_server_bound_cert_service| are shared
     // between |proxy_script_fetcher_context| and |system_request_context|.
     scoped_refptr<net::CookieStore> system_cookie_store;
     scoped_ptr<net::ServerBoundCertService> system_server_bound_cert_service;
     scoped_refptr<extensions::EventRouterForwarder>
         extension_event_router_forwarder;
     scoped_ptr<chrome_browser_net::HttpPipeliningCompatibilityClient>
         http_pipelining_compatibility_client;
     scoped_ptr<chrome_browser_net::LoadTimeStats> load_time_stats;
     scoped_ptr<net::HostMappingRules> host_mapping_rules;
+    scoped_ptr<BasicHttpUserAgentSettings> basic_http_user_agent_settings;

[erikwright (departed), 2012/09/25 21:06:38]

Does this need to be the derived type?

[pauljensen, 2012/09/26 14:08:19]

It doesn't need to be but it seems like the most debugable choice.  I don't have
a preference otherwise.

[erikwright (departed), 2012/09/26 14:19:36]

OK. I think the convention would be to use the least derived type possible to
promote encapsulation. It also makes it easier to change the implementation
later.

     bool ignore_certificate_errors;
     bool http_pipelining_enabled;
     uint16 testing_fixed_http_port;
     uint16 testing_fixed_https_port;
   };
 
   // |net_log| must either outlive the IOThread or be NULL.
   IOThread(PrefService* local_state,
            ChromeNetLog* net_log,
            extensions::EventRouterForwarder* extension_event_router_forwarder);
@@ skipping 93 matching lines @@
       system_url_request_context_getter_;
 
   net::SdchManager* sdch_manager_;
 
   base::WeakPtrFactory<IOThread> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(IOThread);
 };
 
 #endif  // CHROME_BROWSER_IO_THREAD_H_