Add MessagePipe interface. Use it in ChannelDispatcherBase.

remoting/protocol/channel_dispatcher_base.cc

Index: remoting/protocol/channel_dispatcher_base.cc
diff --git a/remoting/protocol/channel_dispatcher_base.cc b/remoting/protocol/channel_dispatcher_base.cc
index 36d60dde564fe4d65cc19ccb77e1d8bd46c0b1c0..64d29a77f50c8eaba55dfbe472a3624143559103 100644
--- a/remoting/protocol/channel_dispatcher_base.cc
+++ b/remoting/protocol/channel_dispatcher_base.cc
@@ -41,16 +41,11 @@ void ChannelDispatcherBase::OnChannelReady(
   }
 
   channel_factory_ = nullptr;
-  channel_ = std::move(socket);
-  writer_.Start(
-      base::Bind(&P2PStreamSocket::Write, base::Unretained(channel_.get())),
-      base::Bind(&ChannelDispatcherBase::OnReadWriteFailed,
-                 base::Unretained(this)));
-  reader_.StartReading(channel_.get(),
-                       base::Bind(&ChannelDispatcherBase::OnIncomingMessage,
-                                  base::Unretained(this)),
-                       base::Bind(&ChannelDispatcherBase::OnReadWriteFailed,
-                                  base::Unretained(this)));
+  message_pipe_.Initialize(
+      std::move(socket),
+      base::Bind(&ChannelDispatcherBase::OnPipeError, base::Unretained(this)));
+  message_pipe_.StartReceiving(base::Bind(
+      &ChannelDispatcherBase::OnIncomingMessage, base::Unretained(this)));
 
   event_handler_->OnChannelInitialized(this);
 }
@@ -62,7 +57,7 @@ void ChannelDispatcherBase::OnIncomingMessage(
   LOG(ERROR) << "Received unexpected message on " << channel_name();
 }
 
-void ChannelDispatcherBase::OnReadWriteFailed(int error) {
+void ChannelDispatcherBase::OnPipeError(int error) {
   event_handler_->OnChannelError(this, CHANNEL_CONNECTION_ERROR);
 }