Remove the mojo serial interfaces and related infrastructure.

device/serial/serial.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";
-
 struct DeviceInfo {
   string path;
   uint16 vendor_id;
   bool has_vendor_id = false;
   uint16 product_id;
   bool has_product_id = false;
   string? display_name;
 };
 
 enum SendError {
@@ skipping 59 matching lines @@
   bool rts;
   bool has_rts = false;
 };
 
 struct DeviceControlSignals {
   bool dcd;
   bool cts;
   bool ri;
   bool dsr;
 };
-
-interface SerialService {
-  GetDevices() => (array<DeviceInfo> devices);
-
-  // Creates a |Connection| to |path| with options specified by |options|,
-  // returning it via |connection|. Sending and receiving data over this
-  // connection is handled by |sink| and |source|, respectively. This will fail
-  // and |connection| will not be usable if |path| does not specify a valid
-  // serial device or there is an error connecting to or configuring the
-  // connection.
-  Connect(string path,
-          ConnectionOptions? options,
-          Connection& connection,
-          DataSink& sink,
-          DataSource& source,
-          DataSourceClient source_client);
-};
-
-interface Connection {
-  GetInfo() => (ConnectionInfo? info);
-  SetOptions(ConnectionOptions options) => (bool success);
-  SetControlSignals(HostControlSignals signals) => (bool success);
-  GetControlSignals() => (DeviceControlSignals? signals);
-  Flush() => (bool success);
-};