add device type as an argument in OnDevicesChanged.

content/browser/system_message_window_win_unittest.cc

 // Copyright (c) 2012 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 "content/browser/system_message_window_win.h"
 
 #include <dbt.h>
 #include <string>
 #include <vector>
 
@@ skipping 12 matching lines @@
     system_monitor_.AddDevicesChangedObserver(&observer_);
   }
 
   MessageLoop message_loop_;
   base::SystemMonitor system_monitor_;
   base::MockDevicesChangedObserver observer_;
   SystemMessageWindowWin window_;
 };
 
 TEST_F(SystemMessageWindowWinTest, DevicesChanged) {
-  EXPECT_CALL(observer_, OnDevicesChanged()).Times(1);
+  EXPECT_CALL(observer_, OnDevicesChanged(testing::_)).Times(1);
   window_.OnDeviceChange(DBT_DEVNODES_CHANGED, NULL);
   message_loop_.RunAllPending();
 }
 
 TEST_F(SystemMessageWindowWinTest, RandomMessage) {
   window_.OnDeviceChange(DBT_DEVICEQUERYREMOVE, NULL);
   message_loop_.RunAllPending();
 }