Implement break signal for serial api.

device/serial/serial_io_handler_win.cc

Index: device/serial/serial_io_handler_win.cc
diff --git a/device/serial/serial_io_handler_win.cc b/device/serial/serial_io_handler_win.cc
index 60a2a332745679ee2c6eba789096ef26b3227a37..c08e3677635c2d20290b056d394137141feb55e8 100644
--- a/device/serial/serial_io_handler_win.cc
+++ b/device/serial/serial_io_handler_win.cc
@@ -391,6 +391,14 @@ serial::ConnectionInfoPtr SerialIoHandlerWin::GetPortInfo() const {
   return info.Pass();
 }
 
+bool SerialIoHandlerWin::SetBreak() {
+  return SetCommBreak(file().GetPlatformFile()) != 0;

[Reilly Grant (use Gerrit), 2015/06/10 19:42:13]

And here.

[limasdf, 2015/06/11 22:14:24]

Done.

+}
+
+bool SerialIoHandlerWin::ClearBreak() {
+  return ClearCommBreak(file().GetPlatformFile()) != 0;

[Reilly Grant (use Gerrit), 2015/06/10 19:42:13]

And here.

[limasdf, 2015/06/11 22:14:24]

Done.

+}
+
 std::string SerialIoHandler::MaybeFixUpPortName(const std::string& port_name) {
   // For COM numbers less than 9, CreateFile is called with a string such as
   // "COM1". For numbers greater than 9, a prefix of "\\\\.\\" must be added.