Pass Mach message trailers to server handler functions

util/mach/child_port_server.cc

Index: util/mach/child_port_server.cc
diff --git a/util/mach/child_port_server.cc b/util/mach/child_port_server.cc
index b263b9049f3acfefcad71a081551d3ea05ab330f..2118d037c4990b6c79b39371ed2b4a8c24372375 100644
--- a/util/mach/child_port_server.cc
+++ b/util/mach/child_port_server.cc
@@ -72,6 +72,9 @@ bool ChildPortServer::MachMessageServerFunction(
     bool* destroy_complex_request) {
   PrepareMIGReplyFromRequest(in_header, out_header);
 
+  const mach_msg_trailer_t* in_trailer =
+      MachMessageTrailerFromHeader(in_header);
+
   switch (in_header->msgh_id) {
     case kMachMessageIDChildPortCheckIn: {
       // child_port_check_in(), handle_child_port_check_in().
@@ -90,6 +93,7 @@ bool ChildPortServer::MachMessageServerFunction(
                                              in_request->token,
                                              in_request->port.name,
                                              in_request->port.disposition,
+                                             in_trailer,
                                              destroy_complex_request);
       return true;
     }