Remove stale-while-revalidate experimental implementation.

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 <vector>
 
@@ skipping 146 matching lines @@
     // between |proxy_script_fetcher_context| and |system_request_context|.
     scoped_refptr<net::CookieStore> system_cookie_store;
 #if defined(ENABLE_EXTENSIONS)
     scoped_refptr<extensions::EventRouterForwarder>
         extension_event_router_forwarder;
 #endif
     scoped_ptr<net::HostMappingRules> host_mapping_rules;
     scoped_ptr<net::HttpUserAgentSettings> http_user_agent_settings;
     scoped_ptr<net::NetworkQualityEstimator> network_quality_estimator;
     bool ignore_certificate_errors;
-    bool use_stale_while_revalidate;
     uint16 testing_fixed_http_port;
     uint16 testing_fixed_https_port;
     Optional<bool> enable_tcp_fast_open_for_ssl;
 
     Optional<size_t> initial_max_spdy_concurrent_streams;
     Optional<bool> enable_spdy_compression;
     Optional<bool> enable_spdy_ping_based_connection_checking;
     Optional<net::NextProto> spdy_default_protocol;
     net::NextProtoVector next_protos;
     Optional<std::string> trusted_spdy_proxy;
@@ skipping 302 matching lines @@
   bool is_quic_allowed_by_policy_;
 
   const base::TimeTicks creation_time_;
 
   base::WeakPtrFactory<IOThread> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(IOThread);
 };
 
 #endif  // CHROME_BROWSER_IO_THREAD_H_