ipc: Update MachPortMac ownership semantics.

ipc/mach_port_mac.cc

Index: ipc/mach_port_mac.cc
diff --git a/ipc/mach_port_mac.cc b/ipc/mach_port_mac.cc
index 96f4acaeb214a42ee982305674de6f01c9115a82..64f7956b75a746ac0b13b3a6b937531b8c92306a 100644
--- a/ipc/mach_port_mac.cc
+++ b/ipc/mach_port_mac.cc
@@ -5,13 +5,23 @@
 #include "ipc/mach_port_mac.h"
 
 #include "base/logging.h"
+#include "base/mac/mach_logging.h"
 #include "base/memory/ref_counted.h"
 #include "base/strings/string_number_conversions.h"
 #include "ipc/mach_port_attachment_mac.h"
 
 namespace IPC {
 
-// static
+MachPortMac::MachPortMac(const mach_port_t& mach_port) : mach_port_(mach_port) {
+  if (mach_port != MACH_PORT_NULL) {
+    kern_return_t kr = mach_port_mod_refs(mach_task_self(), mach_port,
+                                          MACH_PORT_RIGHT_SEND, 1);
+    MACH_LOG_IF(ERROR, kr != KERN_SUCCESS, kr)
+        << "MachPortMac mach_port_mod_refs";
+  }
+}
+
+  // static
 void ParamTraits<MachPortMac>::Write(Message* m, const param_type& p) {
   if (!m->WriteAttachment(
           new IPC::internal::MachPortAttachmentMac(p.get_mach_port()))) {