Retry requests on reused sockets when receiving 408 responses.

408s indicate a socket was left idle for too long before
sending a request.

It's possible these errors are being surfaced to users more often
than previously due to https://codereview.chromium.org/169643006,
for servers that very aggressively time out never-used sockets.

BUG=377581

Review URL: https://codereview.chromium.org/303443011

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@274760 0039d316-1c4b-4281-b951-d872f2087c98

net/base/net_log_event_type_list.h

@@ -1024,7 +1024,9 @@ EVENT_TYPE(HTTP_TRANSACTION_DRAIN_BODY_FOR_AUTH_RESTART)
 // This event is sent when we try to restart a transaction after an error.
 // The following parameters are attached:
 //   {
-//     "net_error": <The net error code integer for the failure>,
+//     "net_error": <The net error code integer for the failure, if applicable>,
+//     "http_status_code": <HTTP status code indicating an error, if
+//                          applicable>,
 //   }
 EVENT_TYPE(HTTP_TRANSACTION_RESTART_AFTER_ERROR)
 

net/http/http_network_transaction.cc

@@ -987,6 +987,19 @@ int HttpNetworkTransaction::DoReadHeadersComplete(int result) {
 
   DCHECK(response_.headers.get());
 
+  // On a 408 response from the server ("Request Timeout") on a stale socket,
+  // retry the request.
+  if (response_.headers->response_code() == 408 &&
+      stream_->IsConnectionReused()) {
+    net_log_.AddEventWithNetErrorCode(
+        NetLog::TYPE_HTTP_TRANSACTION_RESTART_AFTER_ERROR,
+        response_.headers->response_code());
+    // This will close the socket - it would be weird to try and reuse it, even
+    // if the server doesn't actually close it.
+    ResetConnectionAndRequestForResend();
+    return OK;
+  }
+
 #if defined(SPDY_PROXY_AUTH_ORIGIN)
   // Server-induced fallback; see: http://crbug.com/143712
   if (response_.was_fetched_via_proxy) {

net/http/http_network_transaction_unittest.cc

@@ -1439,6 +1439,17 @@ TEST_P(HttpNetworkTransactionTest, KeepAliveConnectionEOF) {
   KeepAliveConnectionResendRequestTest(NULL, &read_failure);
 }
 
+// Make sure that on a 408 response (Request Timeout), the request is retried,
+// if the socket was a reused keep alive socket.
+TEST_P(HttpNetworkTransactionTest, KeepAlive408) {
+  MockRead read_failure(SYNCHRONOUS,
+                        "HTTP/1.1 408 Request Timeout\r\n"
+                        "Connection: Keep-Alive\r\n"
+                        "Content-Length: 6\r\n\r\n"
+                        "Pickle");
+  KeepAliveConnectionResendRequestTest(NULL, &read_failure);
+}
+
 TEST_P(HttpNetworkTransactionTest,
        PreconnectErrorNotConnectedOnWrite) {
   MockWrite write_failure(ASYNC, ERR_SOCKET_NOT_CONNECTED);
@@ -1460,6 +1471,18 @@ TEST_P(HttpNetworkTransactionTest, PreconnectErrorAsyncEOF) {
   PreconnectErrorResendRequestTest(NULL, &read_failure, false);
 }
 
+// Make sure that on a 408 response (Request Timeout), the request is retried,
+// if the socket was a preconnected (UNUSED_IDLE) socket.
+TEST_P(HttpNetworkTransactionTest, RetryOnIdle408) {
+  MockRead read_failure(SYNCHRONOUS,
+                        "HTTP/1.1 408 Request Timeout\r\n"
+                        "Connection: Keep-Alive\r\n"
+                        "Content-Length: 6\r\n\r\n"
+                        "Pickle");
+  KeepAliveConnectionResendRequestTest(NULL, &read_failure);
+  PreconnectErrorResendRequestTest(NULL, &read_failure, false);
+}
+
 TEST_P(HttpNetworkTransactionTest,
        SpdyPreconnectErrorNotConnectedOnWrite) {
   MockWrite write_failure(ASYNC, ERR_SOCKET_NOT_CONNECTED);