Simplify data channel creation logic in WebRTC-based protocol

remoting/protocol/stream_message_pipe_adapter.cc

 // Copyright 2016 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 "remoting/protocol/stream_message_pipe_adapter.h"
 
 #include <utility>
 
 #include "base/bind.h"
 #include "base/callback_helpers.h"
@@ skipping 24 matching lines @@
 }
 
 StreamMessagePipeAdapter::~StreamMessagePipeAdapter() {}
 
 void StreamMessagePipeAdapter::Start(EventHandler* event_handler) {
   reader_.StartReading(socket_.get(),
                        base::Bind(&EventHandler::OnMessageReceived,
                                   base::Unretained(event_handler)),
                        base::Bind(&StreamMessagePipeAdapter::CloseOnError,
                                   base::Unretained(this)));
+  event_handler->OnMessagePipeOpen();
 }
 
 void StreamMessagePipeAdapter::Send(google::protobuf::MessageLite* message,
                                     const base::Closure& done) {
   if (writer_)
     writer_->Write(SerializeAndFrameMessage(*message), done);
 }
 
 void StreamMessagePipeAdapter::CloseOnError(int error) {
   // Stop writing on error.
@@ skipping 30 matching lines @@
   if (!socket) {
     error_callback_.Run(net::ERR_FAILED);
     return;
   }
   callback.Run(base::WrapUnique(
       new StreamMessagePipeAdapter(std::move(socket), error_callback_)));
 }
 
 }  // namespace protocol
 }  // namespace remoting