Mojo: Add a MessageInTransit::Swap() method and remove the "PassContents" ctor.

mojo/system/proxy_message_pipe_endpoint.cc

 // Copyright 2013 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/proxy_message_pipe_endpoint.h"
 
 #include <string.h>
 
 #include "base/logging.h"
 #include "mojo/system/channel_endpoint.h"
 #include "mojo/system/local_message_pipe_endpoint.h"
 #include "mojo/system/message_pipe_dispatcher.h"
 
 namespace mojo {
 namespace system {
 
 ProxyMessagePipeEndpoint::ProxyMessagePipeEndpoint()
     : is_running_(false), is_peer_open_(true) {
 }
 
 ProxyMessagePipeEndpoint::ProxyMessagePipeEndpoint(
     LocalMessagePipeEndpoint* local_message_pipe_endpoint,
     bool is_peer_open)
-    : is_running_(false),
-      is_peer_open_(is_peer_open),
-      paused_message_queue_(MessageInTransitQueue::PassContents(),
-                            local_message_pipe_endpoint->message_queue()) {
+    : is_running_(false), is_peer_open_(is_peer_open) {
+  paused_message_queue_.Swap(local_message_pipe_endpoint->message_queue());
   local_message_pipe_endpoint->Close();
 }
 
 ProxyMessagePipeEndpoint::~ProxyMessagePipeEndpoint() {
   DCHECK(!is_running());
   DCHECK(!is_attached());
   DCHECK(paused_message_queue_.IsEmpty());
 }
 
 MessagePipeEndpoint::Type ProxyMessagePipeEndpoint::GetType() const {
@@ skipping 72 matching lines @@
   DCHECK(is_attached());
 
   channel_endpoint_->DetachFromMessagePipe();
   channel_endpoint_ = NULL;
   is_running_ = false;
   paused_message_queue_.Clear();
 }
 
 }  // namespace system
 }  // namespace mojo