[device] Replace MessageLoopProxy usage with ThreadTaskRunnerHandle

device/serial/serial_io_handler_posix.h

Index: device/serial/serial_io_handler_posix.h
diff --git a/device/serial/serial_io_handler_posix.h b/device/serial/serial_io_handler_posix.h
index a124cf0f67cd164568342da3a1193c456e548d99..e8120bc8f8906e91766a03c1c50e2f53a10bee06 100644
--- a/device/serial/serial_io_handler_posix.h
+++ b/device/serial/serial_io_handler_posix.h
@@ -6,6 +6,8 @@
 #define DEVICE_SERIAL_SERIAL_IO_HANDLER_POSIX_H_
 
 #include "base/message_loop/message_loop.h"
+#include "base/single_thread_task_runner.h"
+#include "base/thread_task_runner_handle.h"
 #include "device/serial/serial_io_handler.h"
 
 namespace device {
@@ -26,15 +28,15 @@ class SerialIoHandlerPosix : public SerialIoHandler,
   serial::ConnectionInfoPtr GetPortInfo() const override;
   void RequestAccess(
       const std::string& port,
-      scoped_refptr<base::MessageLoopProxy> file_message_loop,
-      scoped_refptr<base::MessageLoopProxy> ui_message_loop) override;
+      scoped_refptr<base::SingleThreadTaskRunner> file_message_loop,
+      scoped_refptr<base::SingleThreadTaskRunner> ui_message_loop) override;
 
  private:
   friend class SerialIoHandler;
 
   SerialIoHandlerPosix(
-      scoped_refptr<base::MessageLoopProxy> file_thread_message_loop,
-      scoped_refptr<base::MessageLoopProxy> ui_thread_message_loop);
+      scoped_refptr<base::SingleThreadTaskRunner> file_thread_message_loop,
+      scoped_refptr<base::SingleThreadTaskRunner> ui_thread_message_loop);
   ~SerialIoHandlerPosix() override;
 
   // base::MessageLoopForIO::Watcher implementation.