Add async trace events to trace progress of IPC messages

ipc/ipc_channel_nacl.cc

 // Copyright (c) 2012 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/ipc_channel_nacl.h"
 
 #include <errno.h>
 #include <stddef.h>
 #include <sys/nacl_imc_api.h>
 #include <sys/nacl_syscalls.h>
@@ skipping 175 matching lines @@
 
 bool Channel::ChannelImpl::Send(Message* message) {
   DVLOG(2) << "sending message @" << message << " on channel @" << this
            << " with type " << message->type();
   scoped_ptr<Message> message_ptr(message);
 
 #ifdef IPC_MESSAGE_LOG_ENABLED
   Logging::GetInstance()->OnSendMessage(message_ptr.get(), "");
 #endif  // IPC_MESSAGE_LOG_ENABLED
 
+  message->TraceMessageStep();
   output_queue_.push_back(linked_ptr<Message>(message_ptr.release()));
   if (!waiting_connect_)
     return ProcessOutgoingMessages();
 
   return true;
 }
 
 void Channel::ChannelImpl::DidRecvMsg(scoped_ptr<MessageContents> contents) {
   // Close sets the pipe to -1. It's possible we'll get a buffer sent to us from
   // the reader thread after Close is called. If so, we ignore it.
@@ skipping 181 matching lines @@
   // A random name is sufficient validation on posix systems, so we don't need
   // an additional shared secret.
   std::string id = prefix;
   if (!id.empty())
     id.append(".");
 
   return id.append(GenerateUniqueRandomChannelID());
 }
 
 }  // namespace IPC