Create ash memory monitor

ash/system/monitor/tray_monitor.h

Index: ash/system/monitor/tray_monitor.h
diff --git a/ash/system/monitor/tray_monitor.h b/ash/system/monitor/tray_monitor.h
new file mode 100644
index 0000000000000000000000000000000000000000..c397df4cb044693061df853d7a1effdc5ec20266
--- /dev/null
+++ b/ash/system/monitor/tray_monitor.h
@@ -0,0 +1,39 @@
+// 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.
+
+#ifndef ASH_SYSTEM_DATE_TRAY_MONITOR_H_
+#define ASH_SYSTEM_DATE_TRAY_MONITOR_H_
+
+#include "ash/system/tray/system_tray_item.h"
+#include "base/timer.h"
+
+namespace views {
+class Label;
+}
+
+namespace ash {
+namespace internal {
+
+class TrayMonitor : public SystemTrayItem {
+ public:
+  TrayMonitor();
+  virtual ~TrayMonitor();
+
+ private:
+  // Overridden from SystemTrayItem.
+  virtual views::View* CreateTrayView(user::LoginStatus status) OVERRIDE;
+  virtual void DestroyTrayView() OVERRIDE;
+
+  void RefreshStats();
+
+  views::Label* label_;
+  base::RepeatingTimer<TrayMonitor> refresh_timer_;
+
+  DISALLOW_COPY_AND_ASSIGN(TrayMonitor);
+};
+
+}  // namespace internal
+}  // namespace ash
+
+#endif  // ASH_SYSTEM_DATE_TRAY_MONITOR_H_