Update from https://crrev.com/305340

base/mac/scoped_mach_port.cc

Index: base/mac/scoped_mach_port.cc
diff --git a/base/mac/scoped_mach_port.cc b/base/mac/scoped_mach_port.cc
index de94602e36ed4995dac2b1bbab40654208f73c11..13307f2c9d2557d2d858c36791a1b616eb306616 100644
--- a/base/mac/scoped_mach_port.cc
+++ b/base/mac/scoped_mach_port.cc
@@ -25,6 +25,14 @@ void ReceiveRightTraits::Free(mach_port_t port) {
       << "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