Simplify the user agent code some more since after r255534 it's not affected by the site's URL.

chrome/browser/io_thread.cc

Index: chrome/browser/io_thread.cc
===================================================================
--- chrome/browser/io_thread.cc	(revision 255867)
+++ chrome/browser/io_thread.cc	(working copy)
@@ -29,7 +29,6 @@
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/extensions/event_router_forwarder.h"
 #include "chrome/browser/net/async_dns_field_trial.h"
-#include "chrome/browser/net/basic_http_user_agent_settings.h"
 #include "chrome/browser/net/chrome_net_log.h"
 #include "chrome/browser/net/chrome_network_delegate.h"
 #include "chrome/browser/net/chrome_url_request_context.h"
@@ -40,6 +39,7 @@
 #include "chrome/browser/net/proxy_service_factory.h"
 #include "chrome/browser/net/sdch_dictionary_fetcher.h"
 #include "chrome/browser/net/spdyproxy/http_auth_handler_spdyproxy.h"
+#include "chrome/common/chrome_content_client.h"
 #include "chrome/common/chrome_switches.h"
 #include "chrome/common/chrome_version_info.h"
 #include "chrome/common/pref_names.h"
@@ -78,6 +78,7 @@
 #include "net/url_request/data_protocol_handler.h"
 #include "net/url_request/file_protocol_handler.h"
 #include "net/url_request/ftp_protocol_handler.h"
+#include "net/url_request/static_http_user_agent_settings.h"
 #include "net/url_request/url_fetcher.h"
 #include "net/url_request/url_request_job_factory_impl.h"
 #include "net/url_request/url_request_throttler_manager.h"
@@ -644,7 +645,7 @@
   globals_->dns_probe_service.reset(new chrome_browser_net::DnsProbeService());
   globals_->host_mapping_rules.reset(new net::HostMappingRules());
   globals_->http_user_agent_settings.reset(
-      new BasicHttpUserAgentSettings(std::string()));
+      new net::StaticHttpUserAgentSettings(std::string(), GetUserAgent()));
   if (command_line.HasSwitch(switches::kHostRules)) {
     TRACE_EVENT_BEGIN0("startup", "IOThread::InitAsync:SetRulesFromString");
     globals_->host_mapping_rules->SetRulesFromString(