Created multi-process-friendly PowerMonitor interface.

base/power_monitor/power_monitor_source.cc

+// Copyright 2013 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 "base/power_monitor/power_monitor_source.h"
+
+#include "base/power_monitor/power_monitor.h"
+
+namespace base {
+
+PowerMonitorSource::PowerMonitorSource()
+    : battery_in_use_(false),
+      suspended_(false) {
+}
+
+PowerMonitorSource::~PowerMonitorSource() {
+
+}
+
+void PowerMonitorSource::SetMonitor(PowerMonitor* monitor) {
+  monitor_ = monitor;
+}
+
+bool PowerMonitorSource::IsBatteryPower() {
+  NOTIMPLEMENTED();
+  return false;
+}
+
+void PowerMonitorSource::ProcessPowerEvent(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;
+          if (monitor_)
+            monitor_->NotifyPowerStateChange(on_battery);
+        }
+      }
+      break;
+    case RESUME_EVENT:
+      if (suspended_) {
+        suspended_ = false;
+        if (monitor_)
+          monitor_->NotifyResume();
+      }
+      break;
+    case SUSPEND_EVENT:
+      if (!suspended_) {
+        suspended_ = true;
+        if (monitor_)
+          monitor_->NotifySuspend();
+      }
+      break;
+  }
+}
+
+}  // namespace base