Implement break signal for serial api.

device/serial/serial_io_handler_posix.cc

 // 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.
 
 #include "device/serial/serial_io_handler_posix.h"
 
 #include <sys/ioctl.h>
 #include <termios.h>
 
 #include "base/posix/eintr_wrapper.h"
@@ skipping 454 matching lines @@
                                                  : serial::PARITY_BIT_EVEN;
   } else {
     info->parity_bit = serial::PARITY_BIT_NO;
   }
   info->stop_bits =
       (config.c_cflag & CSTOPB) ? serial::STOP_BITS_TWO : serial::STOP_BITS_ONE;
   info->cts_flow_control = (config.c_cflag & CRTSCTS) != 0;
   return info.Pass();
 }
 
+bool SerialIoHandlerPosix::SetBreak() {
+  if (ioctl(file().GetPlatformFile(), TIOCSBRK, 0) != 0) {
+    VPLOG(1) << "Failed to set break";
+    return false;
+  }
+
+  return true;
+}
+
+bool SerialIoHandlerPosix::ClearBreak() {
+  if (ioctl(file().GetPlatformFile(), TIOCCBRK, 0) != 0) {
+    VPLOG(1) << "Failed to clear break";
+    return false;
+  }
+  return true;
+}
+
 std::string SerialIoHandler::MaybeFixUpPortName(const std::string& port_name) {
   return port_name;
 }
 
 }  // namespace device