Remove use of deprecated MessageLoop methods in device.

device/serial/data_source_sender.cc

Index: device/serial/data_source_sender.cc
diff --git a/device/serial/data_source_sender.cc b/device/serial/data_source_sender.cc
index 31765cbc8f41a82cae94a0cba9602a08837ecf3b..c623bad85473b247b2a83c37f4e69744a72ec850 100644
--- a/device/serial/data_source_sender.cc
+++ b/device/serial/data_source_sender.cc
@@ -10,7 +10,9 @@
 #include <utility>
 
 #include "base/bind.h"
-#include "base/message_loop/message_loop.h"
+#include "base/location.h"
+#include "base/single_thread_task_runner.h"
+#include "base/threading/thread_task_runner_handle.h"
 
 namespace device {
 
@@ -138,7 +140,7 @@ void DataSourceSender::GetMoreData() {
 void DataSourceSender::Done(const std::vector<char>& data) {
   DoneInternal(data);
   if (!shut_down_ && available_buffer_capacity_) {
-    base::MessageLoop::current()->PostTask(
+    base::ThreadTaskRunnerHandle::Get()->PostTask(
         FROM_HERE,
         base::Bind(&DataSourceSender::GetMoreData, weak_factory_.GetWeakPtr()));
   }