Pass Mach message trailers to server handler functions

util/mach/child_port_server.h

Index: util/mach/child_port_server.h
diff --git a/util/mach/child_port_server.h b/util/mach/child_port_server.h
index 4d4e7d8c71afa390bad6bcf86b208b1b3c485c4d..8083a1e8188754977119755cb3a948d788ea2e8f 100644
--- a/util/mach/child_port_server.h
+++ b/util/mach/child_port_server.h
@@ -35,6 +35,7 @@ class ChildPortServer : public MachMessageServer::Interface {
     //! This behaves equivalently to a `handle_child_port_check_in()` function
     //! used with `child_port_server()`.
     //!
+    //! \param[in] trailer The trailer received with the request message.
     //! \param[out] destroy_request `true` if the request message is to be
     //!     destroyed even when this method returns success. See
     //!     MachMessageServer::Interface.
@@ -43,6 +44,7 @@ class ChildPortServer : public MachMessageServer::Interface {
         const child_port_token_t token,
         mach_port_t port,
         mach_msg_type_name_t right_type,
+        const mach_msg_trailer_t* trailer,
         bool* destroy_complex_request) = 0;
 
    protected: