Make SystemMonitor not a Singleton and move it out of base

app/system_monitor_win.cc

-// Copyright (c) 2008 The Chromium Authors. All rights reserved.
+// Copyright (c) 2009 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 "base/system_monitor.h"
-
-namespace base {
+#include "app/system_monitor.h"
 
 void SystemMonitor::ProcessWmPowerBroadcastMessage(int event_id) {
   PowerEvent power_event;
   switch (event_id) {
     case PBT_APMPOWERSTATUSCHANGE:  // The power status changed.
       power_event = POWER_STATE_EVENT;
       break;
     case PBT_APMRESUMEAUTOMATIC:  // Resume from suspend.
     //case PBT_APMRESUMESUSPEND:  // User-initiated resume from suspend.
                                   // We don't notify for this latter event
@@ skipping 21 matching lines @@
 // Function to query the system to see if it is currently running on
 // battery power.  Returns true if running on battery.
 bool SystemMonitor::IsBatteryPower() {
   SYSTEM_POWER_STATUS status;
   if (!GetSystemPowerStatus(&status)) {
     LOG(ERROR) << "GetSystemPowerStatus failed: " << GetLastError();
     return false;
   }
   return (status.ACLineStatus == 0);
 }
-
-
-
-} // namespace base