Remove the mojo serial interfaces and related infrastructure.

device/serial/data_stream_serialization.mojom

-// Copyright 2014 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.
-
-module device.serial;
-
-import "data_stream.mojom";
-
-// A serialized form of a DataSender.
-struct SerializedDataSender {
-  // The control channel to the DataSink to which this DataSender sends data.
-  DataSink sink;
-
-  // The error to report for sends in progress when a fatal error occurs.
-  int32 fatal_error_value;
-};
-
-// A pending receive error.
-struct PendingReceiveError {
-  // The value of the error.
-  int32 error;
-
-  // The location of the error.
-  uint32 offset;
-};
-
-// A serialized form of a DataReceiver.
-struct SerializedDataReceiver {
-  // The control channel to the DataSource from which this DataReceiver receives
-  // data.
-  DataSource source;
-  // DataSourceClient&
-  handle<message_pipe> client;
-
-  // The error to report for a receive in progress when a fatal error occurs.
-  int32 fatal_error_value;
-
-  // The number of bytes this DataReceiver has received from the DataSource.
-  uint32 bytes_received;
-
-  // Whether a Resume() message needs to be sent to the DataSource for it to
-  // resume sending data.
-  bool paused;
-
-  // The pending receive error if there is one.
-  PendingReceiveError? pending_error;
-
-  array<array<uint8>> pending_data;
-};