Make SystemMonitor not a Singleton and move it out of base

SystemMonitor makes an assumption that through its lifetime a MessageLoop exists and stays the same. It is difficult and error-prone to satisfy that when it is a Singleton. It has caused problems in the past.

Additionally, extract HighResoltionTimerManager out of time_win.cc, eliminating yet another Singleton.

TEST=none
BUG=none

Review URL: http://codereview.chromium.org/431008

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@33214 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 29 insertions, 0 deletions

diff --git a/app/hi_res_timer_manager.h b/app/hi_res_timer_manager.h
new file mode 100644
index 0000000..17a0522
--- /dev/null
+++ b/app/hi_res_timer_manager.h
@@ -0,0 +1,29 @@
+// 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.
+
+#ifndef APP_HI_RES_TIMER_MANAGER_H_
+#define APP_HI_RES_TIMER_MANAGER_H_
+
+#include "app/system_monitor.h"
+
+// Ensures that the Windows high resolution timer is only used
+// when not running on battery power.
+class HighResolutionTimerManager : public SystemMonitor::PowerObserver {
+ public:
+  HighResolutionTimerManager();
+  virtual ~HighResolutionTimerManager();
+
+  // SystemMonitor::PowerObserver:
+  void OnPowerStateChange(bool on_battery_power);
+
+ private:
+  // Enable or disable the faster multimedia timer.
+  void UseHiResClock(bool use);
+
+  bool hi_res_clock_used_;
+
+  DISALLOW_COPY_AND_ASSIGN(HighResolutionTimerManager);
+};
+
+#endif  // APP_HI_RES_TIMER_MANAGER_H_