Add async trace events to trace progress of IPC messages

ipc/ipc_channel_proxy.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 "base/bind.h"
 #include "base/compiler_specific.h"
 #include "base/debug/trace_event.h"
 #include "base/location.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/scoped_ptr.h"
@@ skipping 333 matching lines @@
   context_->Clear();
 
   if (context_->ipc_task_runner()) {
     context_->ipc_task_runner()->PostTask(
         FROM_HERE, base::Bind(&Context::OnChannelClosed, context_.get()));
   }
 }
 
 bool ChannelProxy::Send(Message* message) {
   DCHECK(did_init_);
+  message->TraceMessageStep();
   if (outgoing_message_filter())
     message = outgoing_message_filter()->Rewrite(message);
 
 #ifdef IPC_MESSAGE_LOG_ENABLED
   Logging::GetInstance()->OnSendMessage(message, context_->channel_id());
 #endif
 
   context_->ipc_task_runner()->PostTask(
       FROM_HERE,
       base::Bind(&ChannelProxy::Context::OnSendMessage,
@@ skipping 36 matching lines @@
   Channel* channel = context_.get()->channel_.get();
   // Channel must have been created first.
   DCHECK(channel) << context_.get()->channel_id_;
   return channel->GetClientEuid(client_euid);
 }
 #endif
 
 //-----------------------------------------------------------------------------
 
 }  // namespace IPC