ipc: Update MachPortMac ownership semantics.

ipc/ipc_channel_posix.cc

Index: ipc/ipc_channel_posix.cc
diff --git a/ipc/ipc_channel_posix.cc b/ipc/ipc_channel_posix.cc
index b9ab794e4f3746a3dba2bf5de26b2024946d2065..abe2f98a498d645481a5af5edf991e9e63ba0d28 100644
--- a/ipc/ipc_channel_posix.cc
+++ b/ipc/ipc_channel_posix.cc
@@ -697,8 +697,8 @@ bool ChannelPosix::ProcessMessageForDelivery(Message* message) {
   if (message->HasBrokerableAttachments()) {
     DCHECK(GetAttachmentBroker());
     DCHECK(peer_pid_ != base::kNullProcessId);
-    for (const BrokerableAttachment* attachment :
-         message->attachment_set()->PeekBrokerableAttachments()) {
+    for (BrokerableAttachment* attachment :
+         message->attachment_set()->GetBrokerableAttachments()) {
       if (!GetAttachmentBroker()->SendAttachmentToProcess(attachment,
                                                           peer_pid_)) {
         delete message;