Provide mutable members of UrlRequestContext via pure-virtual interface

chrome/service/net/service_url_request_context.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_SERVICE_NET_SERVICE_URL_REQUEST_CONTEXT_H_
 #define CHROME_SERVICE_NET_SERVICE_URL_REQUEST_CONTEXT_H_
 
 #include <string>
 
 #include "base/memory/scoped_ptr.h"
@@ skipping 23 matching lines @@
 //
 class ServiceURLRequestContext : public net::URLRequestContext {
  public:
   // This context takes ownership of |net_proxy_config_service|.
   explicit ServiceURLRequestContext(
       const std::string& user_agent,
       net::ProxyConfigService* net_proxy_config_service);
 
   virtual ~ServiceURLRequestContext();
 
-  // Overridden from net::URLRequestContext:
-  virtual const std::string& GetUserAgent(const GURL& url) const OVERRIDE;
-
  private:
-  std::string user_agent_;
   net::URLRequestContextStorage storage_;
 };
 
 class ServiceURLRequestContextGetter : public net::URLRequestContextGetter {
  public:
   virtual net::URLRequestContext* GetURLRequestContext() OVERRIDE;
   virtual scoped_refptr<base::SingleThreadTaskRunner>
       GetNetworkTaskRunner() const OVERRIDE;
 
   void set_user_agent(const std::string& ua) {
     user_agent_ = ua;
   }
   std::string user_agent() const {
     return user_agent_;
   }
 
  private:
   friend class ServiceProcess;
   ServiceURLRequestContextGetter();
   virtual ~ServiceURLRequestContextGetter();
 
   std::string user_agent_;
   scoped_refptr<base::SingleThreadTaskRunner> network_task_runner_;
   scoped_ptr<net::ProxyConfigService> proxy_config_service_;
   scoped_ptr<net::URLRequestContext> url_request_context_;
 };
 
 #endif  // CHROME_SERVICE_NET_SERVICE_URL_REQUEST_CONTEXT_H_