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, 98 insertions, 0 deletions

diff --git a/app/system_monitor.cc b/app/system_monitor.cc
new file mode 100644
index 0000000..b0e715a
--- /dev/null
+++ b/app/system_monitor.cc
@@ -0,0 +1,98 @@
+// 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/system_monitor.h"
+
+#include "base/logging.h"
+#include "base/message_loop.h"
+#include "base/time.h"
+
+static SystemMonitor* g_system_monitor = NULL;
+
+#if defined(ENABLE_BATTERY_MONITORING)
+// The amount of time (in ms) to wait before running the initial
+// battery check.
+static int kDelayedBatteryCheckMs = 10 * 1000;
+#endif  // defined(ENABLE_BATTERY_MONITORING)
+
+SystemMonitor::SystemMonitor()
+    : observer_list_(new ObserverListThreadSafe<PowerObserver>()),
+      battery_in_use_(false),
+      suspended_(false) {
+  DCHECK(!g_system_monitor);
+  g_system_monitor = this;
+
+  DCHECK(MessageLoop::current());
+#if defined(ENABLE_BATTERY_MONITORING)
+  delayed_battery_check_.Start(
+      base::TimeDelta::FromMilliseconds(kDelayedBatteryCheckMs), this,
+      &SystemMonitor::BatteryCheck);
+#endif  // defined(ENABLE_BATTERY_MONITORING)
+}
+
+SystemMonitor::~SystemMonitor() {
+  DCHECK_EQ(this, g_system_monitor);
+  g_system_monitor = NULL;
+}
+
+// static
+SystemMonitor* SystemMonitor::Get() {
+  return g_system_monitor;
+}
+
+void SystemMonitor::ProcessPowerMessage(PowerEvent event_id) {
+  // Suppress duplicate notifications.  Some platforms may
+  // send multiple notifications of the same event.
+  switch (event_id) {
+    case POWER_STATE_EVENT:
+      {
+        bool on_battery = IsBatteryPower();
+        if (on_battery != battery_in_use_) {
+          battery_in_use_ = on_battery;
+          NotifyPowerStateChange();
+        }
+      }
+      break;
+    case RESUME_EVENT:
+      if (suspended_) {
+        suspended_ = false;
+        NotifyResume();
+      }
+      break;
+    case SUSPEND_EVENT:
+      if (!suspended_) {
+        suspended_ = true;
+        NotifySuspend();
+      }
+      break;
+  }
+}
+
+void SystemMonitor::AddObserver(PowerObserver* obs) {
+  observer_list_->AddObserver(obs);
+}
+
+void SystemMonitor::RemoveObserver(PowerObserver* obs) {
+  observer_list_->RemoveObserver(obs);
+}
+
+void SystemMonitor::NotifyPowerStateChange() {
+  LOG(INFO) << L"PowerStateChange: "
+           << (BatteryPower() ? L"On" : L"Off") << L" battery";
+  observer_list_->Notify(&PowerObserver::OnPowerStateChange, BatteryPower());
+}
+
+void SystemMonitor::NotifySuspend() {
+  LOG(INFO) << L"Power Suspending";
+  observer_list_->Notify(&PowerObserver::OnSuspend);
+}
+
+void SystemMonitor::NotifyResume() {
+  LOG(INFO) << L"Power Resuming";
+  observer_list_->Notify(&PowerObserver::OnResume);
+}
+
+void SystemMonitor::BatteryCheck() {
+  ProcessPowerMessage(SystemMonitor::POWER_STATE_EVENT);
+}