Record errors that trigger a data reduction proxy bypass

net/http/http_network_transaction.cc

Index: net/http/http_network_transaction.cc
diff --git a/net/http/http_network_transaction.cc b/net/http/http_network_transaction.cc
index d9397e4cfbc30dd4f8eab5fb3cf1e5233b277590..7783aeecc7ccd0780accd84cad7bafb395e1886a 100644
--- a/net/http/http_network_transaction.cc
+++ b/net/http/http_network_transaction.cc
@@ -1009,6 +1009,14 @@ int HttpNetworkTransaction::DoReadHeadersComplete(int result) {
           = response_.headers->GetDataReductionProxyBypassEventType(
               &data_reduction_proxy_info);
       if (proxy_bypass_event < ProxyService::BYPASS_EVENT_TYPE_MAX) {
+        // Bypass all proxies for one second on reception of a 4xx that
+        // originated at the proxy.
+        if (proxy_bypass_event == ProxyService::PROXY_4XX_BYPASS) {
+          data_reduction_proxy_info.bypass_all = true;
+          data_reduction_proxy_info.bypass_duration =
+              base::TimeDelta::FromSeconds(1);
+        }
+
         ProxyService* proxy_service = session_->proxy_service();
 
         proxy_service->RecordDataReductionProxyBypassInfo(