Make SystemMonitor not a Singleton and move it out of base

views/widget/widget_win.cc

Index: views/widget/widget_win.cc
diff --git a/views/widget/widget_win.cc b/views/widget/widget_win.cc
index 79956a80cc51b23bcd8dd6d5e7fa58d464e63350..892d47fbac46200f31e8b0bf9f6df645b16021d4 100644
--- a/views/widget/widget_win.cc
+++ b/views/widget/widget_win.cc
@@ -8,6 +8,7 @@
 #include "app/gfx/native_theme_win.h"
 #include "app/gfx/path.h"
 #include "app/l10n_util_win.h"
+#include "app/system_monitor.h"
 #include "app/win_util.h"
 #include "base/string_util.h"
 #include "base/win_util.h"
@@ -770,7 +771,7 @@ void WidgetWin::OnPaint(HDC dc) {
 }
 
 LRESULT WidgetWin::OnPowerBroadcast(DWORD power_event, DWORD data) {
-  base::SystemMonitor* monitor = base::SystemMonitor::Get();
+  SystemMonitor* monitor = SystemMonitor::Get();
   if (monitor)
     monitor->ProcessWmPowerBroadcastMessage(power_event);
   SetMsgHandled(FALSE);