Implement break signal for serial api.

device/serial/test_serial_io_handler.h

 // 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.
 
 #ifndef DEVICE_SERIAL_TEST_SERIAL_IO_HANDLER_H_
 #define DEVICE_SERIAL_TEST_SERIAL_IO_HANDLER_H_
 
 #include <string>
 
 #include "base/callback.h"
@@ skipping 14 matching lines @@
             const OpenCompleteCallback& callback) override;
   void ReadImpl() override;
   void CancelReadImpl() override;
   void WriteImpl() override;
   void CancelWriteImpl() override;
   bool ConfigurePortImpl() override;
   serial::DeviceControlSignalsPtr GetControlSignals() const override;
   serial::ConnectionInfoPtr GetPortInfo() const override;
   bool Flush() const override;
   bool SetControlSignals(const serial::HostControlSignals& signals) override;
+  bool SetBreak() override;
+  bool ClearBreak() override;
 
   serial::ConnectionInfo* connection_info() { return &info_; }
   serial::DeviceControlSignals* device_control_signals() {
     return &device_control_signals_;
   }
   bool dtr() { return dtr_; }
   bool rts() { return rts_; }
   int flushes() { return flushes_; }
   // This callback will be called when this IoHandler processes its next write,
   // instead of the normal behavior of echoing the data to reads.
@@ skipping 13 matching lines @@
   mutable int flushes_;
   std::string buffer_;
   base::Closure send_callback_;
 
   DISALLOW_COPY_AND_ASSIGN(TestSerialIoHandler);
 };
 
 }  // namespace device
 
 #endif  // DEVICE_SERIAL_TEST_SERIAL_IO_HANDLER_H_