Add POSIX shared memory support for Mac

ipc/ipc_message_utils.cc

Index: ipc/ipc_message_utils.cc
diff --git a/ipc/ipc_message_utils.cc b/ipc/ipc_message_utils.cc
index be83e5a236bb2322e66b36d13aa0640759cdc691..d96266f6f27edb8299f856e411cb5e41730d5283 100644
--- a/ipc/ipc_message_utils.cc
+++ b/ipc/ipc_message_utils.cc
@@ -690,22 +690,43 @@ void ParamTraits<base::SharedMemoryHandle>::GetSize(base::PickleSizer* sizer,
 
 void ParamTraits<base::SharedMemoryHandle>::Write(base::Pickle* m,
                                                   const param_type& p) {
-  MachPortMac mach_port_mac(p.GetMemoryObject());
-  ParamTraits<MachPortMac>::Write(m, mach_port_mac);
-  size_t size = 0;
-  bool result = p.GetSize(&size);
-  DCHECK(result);
-  ParamTraits<uint32_t>::Write(m, static_cast<uint32_t>(size));
+  m->WriteInt(p.GetType());
 
-  // If the caller intended to pass ownership to the IPC stack, release a
-  // reference.
-  if (p.OwnershipPassesToIPC())
-    p.Close();
+  switch (p.GetType()) {
+    case base::SharedMemoryHandle::POSIX:
+      // We should never pass POSIX shared memory over IPC.
+      CHECK(false);
+      break;
+    case base::SharedMemoryHandle::MACH:
+      MachPortMac mach_port_mac(p.GetMemoryObject());
+      ParamTraits<MachPortMac>::Write(m, mach_port_mac);
+      size_t size = 0;
+      bool result = p.GetSize(&size);
+      DCHECK(result);
+      ParamTraits<uint32_t>::Write(m, static_cast<uint32_t>(size));
+
+      // If the caller intended to pass ownership to the IPC stack, release a
+      // reference.
+      if (p.OwnershipPassesToIPC())
+        p.Close();
+
+      break;
+  }
 }
 
 bool ParamTraits<base::SharedMemoryHandle>::Read(const base::Pickle* m,
                                                  base::PickleIterator* iter,
                                                  param_type* r) {
+  base::SharedMemoryHandle::TypeWireFormat type;
+  if (!iter->ReadInt(&type))
+    return false;
+
+  if (type == base::SharedMemoryHandle::POSIX) {
+    // We should never pass POSIX shared memory over IPC.
+    CHECK(false);
+    return false;
+  }
+
   MachPortMac mach_port_mac;
   if (!ParamTraits<MachPortMac>::Read(m, iter, &mach_port_mac))
     return false;
@@ -722,8 +743,16 @@ bool ParamTraits<base::SharedMemoryHandle>::Read(const base::Pickle* m,
 
 void ParamTraits<base::SharedMemoryHandle>::Log(const param_type& p,
                                                 std::string* l) {
-  l->append("Mach port: ");
-  LogParam(p.GetMemoryObject(), l);
+  switch (p.GetType()) {
+    case base::SharedMemoryHandle::POSIX:
+      // We should never pass POSIX shared memory over IPC.
+      CHECK(false);
+      break;
+    case base::SharedMemoryHandle::MACH:
+      l->append("Mach port: ");
+      LogParam(p.GetMemoryObject(), l);
+      break;
+  }
 }
 
 #elif defined(OS_WIN)