Update from https://crrev.com/311076

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 b4ef356df1531babba69f2198a5e639df910d684..97fc7db7664c419b8a492a871bb2927ca0b99e9a 100644
--- a/net/http/http_network_transaction.cc
+++ b/net/http/http_network_transaction.cc
@@ -173,6 +173,9 @@ int HttpNetworkTransaction::Start(const HttpRequestInfo* request_info,
     proxy_ssl_config_.rev_checking_enabled = false;
   }
 
+  if (request_->load_flags & LOAD_PREFETCH)
+    response_.unused_since_prefetch = true;
+
   // Channel ID is disabled if privacy mode is enabled for this request.
   if (request_->privacy_mode == PRIVACY_MODE_ENABLED)
     server_ssl_config_.channel_id_enabled = false;
@@ -746,6 +749,9 @@ int HttpNetworkTransaction::DoCreateStreamComplete(int result) {
     // Return OK and let the caller read the proxy's error page
     next_state_ = STATE_NONE;
     return OK;
+  } else if (result == ERR_HTTP_1_1_REQUIRED ||
+             result == ERR_PROXY_HTTP_1_1_REQUIRED) {
+    return HandleHttp11Required(result);
   }
 
   // Handle possible handshake errors that may have occurred if the stream
@@ -961,6 +967,11 @@ int HttpNetworkTransaction::DoReadHeadersComplete(int result) {
       return result;
   }
 
+  if (result == ERR_HTTP_1_1_REQUIRED ||
+      result == ERR_PROXY_HTTP_1_1_REQUIRED) {
+    return HandleHttp11Required(result);
+  }
+
   // ERR_CONNECTION_CLOSED is treated differently at this point; if partial
   // response headers were received, we do the best we can to make sense of it
   // and send it back up the stack.
@@ -1195,6 +1206,19 @@ int HttpNetworkTransaction::HandleCertificateRequest(int error) {
   return OK;
 }
 
+int HttpNetworkTransaction::HandleHttp11Required(int error) {
+  DCHECK(error == ERR_HTTP_1_1_REQUIRED ||
+         error == ERR_PROXY_HTTP_1_1_REQUIRED);
+
+  if (error == ERR_HTTP_1_1_REQUIRED) {
+    HttpServerProperties::ForceHTTP11(&server_ssl_config_);
+  } else {
+    HttpServerProperties::ForceHTTP11(&proxy_ssl_config_);
+  }
+  ResetConnectionAndRequestForResend();
+  return OK;
+}
+
 void HttpNetworkTransaction::HandleClientAuthError(int error) {
   if (server_ssl_config_.send_client_cert &&
       (error == ERR_SSL_PROTOCOL_ERROR || IsClientCertificateError(error))) {