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, 31 insertions, 0 deletions

diff --git a/app/hi_res_timer_manager_win.cc b/app/hi_res_timer_manager_win.cc
new file mode 100644
index 0000000..b7cee1d
--- /dev/null
+++ b/app/hi_res_timer_manager_win.cc
@@ -0,0 +1,31 @@
+// 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 "app/hi_res_timer_manager.h"
+
+#include "base/time.h"
+
+HighResolutionTimerManager::HighResolutionTimerManager()
+    : hi_res_clock_used_(false) {
+  SystemMonitor* system_monitor = SystemMonitor::Get();
+  system_monitor->AddObserver(this);
+  UseHiResClock(!system_monitor->BatteryPower());
+}
+
+HighResolutionTimerManager::~HighResolutionTimerManager() {
+  SystemMonitor::Get()->RemoveObserver(this);
+  UseHiResClock(false);
+}
+
+void HighResolutionTimerManager::OnPowerStateChange(bool on_battery_power) {
+  UseHiResClock(!on_battery_power);
+}
+
+void HighResolutionTimerManager::UseHiResClock(bool use) {
+  if (use == hi_res_clock_used_)
+    return;
+  bool result = base::Time::UseHighResolutionTimer(use);
+  DCHECK(result);
+  hi_res_clock_used_ = use;
+}