Created multi-process-friendly PowerMonitor interface.

content/common/power_monitor_broadcast_source.cc

+// Copyright (c) 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 "content/common/power_monitor_broadcast_source.h"
+
+#include "base/bind.h"
+#include "base/bind_helpers.h"
+#include "content/common/power_monitor_messages.h"
+
+namespace content {
+
+PowerMonitorBroadcastSource::PowerMonitorBroadcastSource(
+    scoped_refptr<base::MessageLoopProxy> message_loop)
+  : on_battery_power_(false),
+  message_filter_(new PowerMessageFilter(this)),
+  message_loop_(message_loop),
+  weak_factory_(this) {
+}
+
+PowerMonitorBroadcastSource::~PowerMonitorBroadcastSource() {
+}
+
+// MessageFilters are owned by the Channel they are added to, so this class does
+// not need to retain a reference.
+IPC::ChannelProxy::MessageFilter*
+PowerMonitorBroadcastSource::MessageFilter() {
+  return message_filter_.get();
+}
+
+bool PowerMonitorBroadcastSource::IsBatteryPower() {
+  return on_battery_power_;
+}
+
+void PowerMonitorBroadcastSource::OnPowerStateChange(bool on_battery_power) {
+  on_battery_power_ = on_battery_power;

[Ken Russell (switch to Gerrit), 2013/07/03 09:49:43]

Is synchronization needed around this variable? It's modified on the IO thread
and queried on the UI thread.

+  message_loop_->PostTask(FROM_HERE,
+      base::Bind(&PowerMonitorBroadcastSource::ProcessPowerEvent,
+          weak_factory_.GetWeakPtr(), PowerMonitorSource::POWER_STATE_EVENT));
+  //ProcessPowerEvent(PowerMonitorSource::POWER_STATE_EVENT);

[Ken Russell (switch to Gerrit), 2013/07/03 09:49:43]

Here and below: remove commented out code.

+}
+
+void PowerMonitorBroadcastSource::OnSuspend() {
+  message_loop_->PostTask(FROM_HERE,
+      base::Bind(&PowerMonitorBroadcastSource::ProcessPowerEvent,
+          weak_factory_.GetWeakPtr(), PowerMonitorSource::SUSPEND_EVENT));
+  //ProcessPowerEvent(PowerMonitorSource::SUSPEND_EVENT);
+}
+
+void PowerMonitorBroadcastSource::OnResume() {
+  message_loop_->PostTask(FROM_HERE,
+      base::Bind(&PowerMonitorBroadcastSource::ProcessPowerEvent,
+          weak_factory_.GetWeakPtr(), PowerMonitorSource::RESUME_EVENT));
+  //ProcessPowerEvent(PowerMonitorSource::RESUME_EVENT);
+}
+
+PowerMonitorBroadcastSource::PowerMessageFilter::PowerMessageFilter(
+    PowerMonitorBroadcastSource* source) : source_(source) {
+}
+
+PowerMonitorBroadcastSource::PowerMessageFilter::~PowerMessageFilter() {
+}
+
+bool PowerMonitorBroadcastSource::PowerMessageFilter::OnMessageReceived(
+    const IPC::Message& message) {
+  bool msg_is_ok = true;
+  bool handled = true;
+  IPC_BEGIN_MESSAGE_MAP_EX(PowerMessageFilter, message, msg_is_ok)
+    IPC_MESSAGE_HANDLER(PowerMonitorMsg_PowerStateChange, OnPowerStateChange)
+    IPC_MESSAGE_HANDLER(PowerMonitorMsg_Suspend, OnSuspend)
+    IPC_MESSAGE_HANDLER(PowerMonitorMsg_Resume, OnResume)
+    IPC_MESSAGE_UNHANDLED(handled = false)
+  IPC_END_MESSAGE_MAP_EX()
+  return handled;
+}
+
+void PowerMonitorBroadcastSource::PowerMessageFilter::OnPowerStateChange(
+    bool on_battery_power) {
+  source_->OnPowerStateChange(on_battery_power);
+}
+
+void PowerMonitorBroadcastSource::PowerMessageFilter::OnSuspend() {
+  source_->OnSuspend();
+}
+
+void PowerMonitorBroadcastSource::PowerMessageFilter::OnResume() {
+  source_->OnResume();
+}
+
+}  // namespace content