IPC: Remove unnecessary conversions of BrokerableAttachment.

ipc/attachment_broker_unprivileged_mac.cc

 // Copyright 2015 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 "ipc/attachment_broker_unprivileged_mac.h"
 
 #include <mach/mach.h>
 
 #include "base/mac/scoped_mach_port.h"
 #include "base/process/process.h"
@@ skipping 32 matching lines @@
 
 }  // namespace
 
 namespace IPC {
 
 AttachmentBrokerUnprivilegedMac::AttachmentBrokerUnprivilegedMac() {}
 
 AttachmentBrokerUnprivilegedMac::~AttachmentBrokerUnprivilegedMac() {}
 
 bool AttachmentBrokerUnprivilegedMac::SendAttachmentToProcess(
-    BrokerableAttachment* attachment,
+    const scoped_refptr<IPC::BrokerableAttachment>& attachment,
     base::ProcessId destination_process) {
   switch (attachment->GetBrokerableType()) {
     case BrokerableAttachment::MACH_PORT: {
       internal::MachPortAttachmentMac* mach_port_attachment =
-          static_cast<internal::MachPortAttachmentMac*>(attachment);
+          static_cast<internal::MachPortAttachmentMac*>(attachment.get());
       internal::MachPortAttachmentMac::WireFormat format =
           mach_port_attachment->GetWireFormat(destination_process);
       bool success =
           get_sender()->Send(new AttachmentBrokerMsg_DuplicateMachPort(format));
       if (success)
         mach_port_attachment->reset_mach_port_ownership();
       return success;
     }
     default:
       NOTREACHED();
@@ skipping 26 matching lines @@
   IPC::internal::MachPortAttachmentMac::WireFormat translated_wire_format(
       memory_object.release(), wire_format.destination_process,
       wire_format.attachment_id);
 
   scoped_refptr<BrokerableAttachment> attachment(
       new IPC::internal::MachPortAttachmentMac(translated_wire_format));
   HandleReceivedAttachment(attachment);
 }
 
 }  // namespace IPC