Add embedder-specific headers to HTTP CONNECT tunnel request

net/socket/client_socket_pool_manager.cc

Index: net/socket/client_socket_pool_manager.cc
diff --git a/net/socket/client_socket_pool_manager.cc b/net/socket/client_socket_pool_manager.cc
index a7bf1fe5b753bc7796b1019c7260649f06a6bc06..477fe5e4b241e2ac6146a1096b869b775dc3fbcb 100644
--- a/net/socket/client_socket_pool_manager.cc
+++ b/net/socket/client_socket_pool_manager.cc
@@ -189,15 +189,17 @@ int InitSocketPoolHelper(const GURL& request_url,
       }
 
       http_proxy_params =
-          new HttpProxySocketParams(proxy_tcp_params,
-                                    ssl_params,
-                                    request_url,
-                                    user_agent,
-                                    origin_host_port,
-                                    session->http_auth_cache(),
-                                    session->http_auth_handler_factory(),
-                                    session->spdy_session_pool(),
-                                    force_tunnel || using_ssl);
+          new HttpProxySocketParams(
+              proxy_tcp_params,
+              ssl_params,
+              request_url,
+              user_agent,
+              origin_host_port,
+              session->http_auth_cache(),
+              session->http_auth_handler_factory(),
+              session->spdy_session_pool(),
+              force_tunnel || using_ssl,
+              session->params().before_proxy_tunnel_request_callback);
     } else {
       DCHECK(proxy_info.is_socks());
       char socks_version;