Update from https://crrev.com/305340

base/mac/scoped_mach_port.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "base/mac/scoped_mach_port.h"
 
 #include "base/mac/mach_logging.h"
 
 namespace base {
 namespace mac {
 namespace internal {
 
 // static
 void SendRightTraits::Free(mach_port_t port) {
   kern_return_t kr = mach_port_deallocate(mach_task_self(), port);
   MACH_LOG_IF(ERROR, kr != KERN_SUCCESS, kr)
       << "ScopedMachSendRight mach_port_deallocate";
 }
 
 // static
 void ReceiveRightTraits::Free(mach_port_t port) {
   kern_return_t kr =
       mach_port_mod_refs(mach_task_self(), port, MACH_PORT_RIGHT_RECEIVE, -1);
   MACH_LOG_IF(ERROR, kr != KERN_SUCCESS, kr)
       << "ScopedMachReceiveRight mach_port_mod_refs";
 }
 
+// static
+void PortSetTraits::Free(mach_port_t port) {
+  kern_return_t kr =
+      mach_port_mod_refs(mach_task_self(), port, MACH_PORT_RIGHT_PORT_SET, -1);
+  MACH_LOG_IF(ERROR, kr != KERN_SUCCESS, kr)
+      << "ScopedMachPortSet mach_port_mod_refs";
+}
+
 }  // namespace internal
 }  // namespace mac
 }  // namespace base