More fixes for scoped_refptr operator T* removal.

mojo/system/channel_endpoint.cc

 // Copyright 2014 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 "mojo/system/channel_endpoint.h"
 
 #include "mojo/system/channel.h"
 #include "mojo/system/message_in_transit_queue.h"
 
 namespace mojo {
 namespace system {
 
-ChannelEndpoint::ChannelEndpoint(MessagePipe* message_pipe, unsigned port)
+ChannelEndpoint::ChannelEndpoint(const scoped_refptr<MessagePipe>& message_pipe,
+                                 unsigned port)
     : state_(STATE_NORMAL), message_pipe_(message_pipe), port_(port) {
 }
 
 ChannelEndpoint::~ChannelEndpoint() {
 }
 
 }  // namespace system
 }  // namespace mojo