Revert of Remove reference counting from HttpNetworkSession.

chrome/browser/io_thread.h

Index: chrome/browser/io_thread.h
diff --git a/chrome/browser/io_thread.h b/chrome/browser/io_thread.h
index 21b57d33b9fa6b11e2909fdd99ad4d695e52d517..cc943df09cca9d1edd706a42a79219ed706e11ec 100644
--- a/chrome/browser/io_thread.h
+++ b/chrome/browser/io_thread.h
@@ -54,7 +54,6 @@
 class HostMappingRules;
 class HostResolver;
 class HttpAuthHandlerFactory;
-class HttpNetworkSession;
 class HttpServerProperties;
 class HttpTransactionFactory;
 class HttpUserAgentSettings;
@@ -136,8 +135,6 @@
     scoped_ptr<net::HttpAuthHandlerFactory> http_auth_handler_factory;
     scoped_ptr<net::HttpServerProperties> http_server_properties;
     scoped_ptr<net::ProxyService> proxy_script_fetcher_proxy_service;
-    scoped_ptr<net::HttpNetworkSession>
-        proxy_script_fetcher_http_network_session;
     scoped_ptr<net::HttpTransactionFactory>
         proxy_script_fetcher_http_transaction_factory;
     scoped_ptr<net::FtpTransactionFactory>
@@ -154,7 +151,6 @@
     // ProxyService, since we always directly connect to fetch the PAC script.
     scoped_ptr<net::URLRequestContext> proxy_script_fetcher_context;
     scoped_ptr<net::ProxyService> system_proxy_service;
-    scoped_ptr<net::HttpNetworkSession> system_http_network_session;
     scoped_ptr<net::HttpTransactionFactory> system_http_transaction_factory;
     scoped_ptr<net::URLRequestJobFactory> system_url_request_job_factory;
     scoped_ptr<net::URLRequestContext> system_request_context;