Provide mutable members of UrlRequestContext via pure-virtual interface.  Create a pure-virtual interface called HttpUserAgentSettings that provides access to the Accept-Language, Accept-Charset, and User-Agent HTTP headers.  Each UrlRequestContext should have a HttpUserAgentSettings implementation attached via set_http_user_agent_settings().  


BUG=146596

Review URL: https://chromiumcodereview.appspot.com/10918279

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@166425 0039d316-1c4b-4281-b951-d872f2087c98
diff --git a/chrome/browser/io_thread.h b/chrome/browser/io_thread.h
index 6e0699c..ae1af7d 100644
--- a/chrome/browser/io_thread.h
+++ b/chrome/browser/io_thread.h
@@ -41,6 +41,7 @@
 class HttpAuthHandlerFactory;
 class HttpServerProperties;
 class HttpTransactionFactory;
+class HttpUserAgentSettings;
 class NetworkDelegate;
 class ServerBoundCertService;
 class ProxyConfigService;
@@ -115,6 +116,7 @@
         http_pipelining_compatibility_client;
     scoped_ptr<chrome_browser_net::LoadTimeStats> load_time_stats;
     scoped_ptr<net::HostMappingRules> host_mapping_rules;
+    scoped_ptr<net::HttpUserAgentSettings> http_user_agent_settings;
     bool ignore_certificate_errors;
     bool http_pipelining_enabled;
     uint16 testing_fixed_http_port;