Remove calls to deprecated MessageLoop methods on Windows and Linux.

media/device_monitors/system_message_window_win_unittest.cc

Index: media/device_monitors/system_message_window_win_unittest.cc
diff --git a/media/device_monitors/system_message_window_win_unittest.cc b/media/device_monitors/system_message_window_win_unittest.cc
index dff7b5af442f01b53372da0c6c80cf08f8a65655..a6a7dfd0051a68e3e8431268024ccfc20babbd8e 100644
--- a/media/device_monitors/system_message_window_win_unittest.cc
+++ b/media/device_monitors/system_message_window_win_unittest.cc
@@ -10,6 +10,7 @@
 
 #include "base/files/file_path.h"
 #include "base/message_loop/message_loop.h"
+#include "base/run_loop.h"
 #include "base/system_monitor/system_monitor.h"
 #include "base/test/mock_devices_changed_observer.h"
 #include "testing/gmock/include/gmock/gmock.h"
@@ -35,12 +36,12 @@ class SystemMessageWindowWinTest : public testing::Test {
 TEST_F(SystemMessageWindowWinTest, DevicesChanged) {
   EXPECT_CALL(observer_, OnDevicesChanged(testing::_)).Times(1);
   window_.OnDeviceChange(DBT_DEVNODES_CHANGED, NULL);
-  message_loop_.RunUntilIdle();
+  base::RunLoop().RunUntilIdle();
 }
 
 TEST_F(SystemMessageWindowWinTest, RandomMessage) {
   window_.OnDeviceChange(DBT_DEVICEQUERYREMOVE, NULL);
-  message_loop_.RunUntilIdle();
+  base::RunLoop().RunUntilIdle();
 }
 
 }  // namespace media