Created multi-process-friendly PowerMonitor interface.

content/common/power_monitor_message_filter.cc

Index: content/common/power_monitor_message_filter.cc
diff --git a/content/common/power_monitor_message_filter.cc b/content/common/power_monitor_message_filter.cc
new file mode 100644
index 0000000000000000000000000000000000000000..64482de8d5fb923d14a5f0c8017c65e05258ef66
--- /dev/null
+++ b/content/common/power_monitor_message_filter.cc
@@ -0,0 +1,73 @@
+// 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_message_filter.h"
+
+#include "content/common/power_monitor_messages.h"
+
+namespace content {
+
+PowerMonitorBroadcastSource::PowerMonitorBroadcastSource()
+  : on_battery_power_(false) {
+    message_filter_ = new PowerMessageFilter(this);

[vandebo (ex-Chrome), 2013/06/26 21:40:33]

memory leak

[bajones, 2013/06/26 22:37:22]

This is tricky. This filter will be passed to the GpuChannel's
channel_->AddFilter() method, which appears to take ownership of the filter.
Agreed that this is an awkward place to construct it, though. Probably be better
to add a MessageFilter factory method to this class, now that I think about it.

[vandebo (ex-Chrome), 2013/06/26 22:50:12]

If channel_ owns it, are we sure that it won't be deleted while
PowerMonitorBroadcastSource is alive?  If so, a comment in the header above
|message_filter_| explaining why the raw pointer is safe would be helpful.

[Ken Russell (switch to Gerrit), 2013/06/27 13:08:23]

See gpu_channel.cc for an example and ipc_channel_proxy.h for documentation;
MessageFilter is ref-counted. message_filter_ should be
scoped_refptr<PowerMessageFilter>.

+}
+
+PowerMonitorBroadcastSource::~PowerMonitorBroadcastSource() {
+}
+
+IPC::ChannelProxy::MessageFilter* PowerMonitorBroadcastSource::MessageFilter() {
+  return message_filter_;
+}
+
+bool PowerMonitorBroadcastSource::IsBatteryPower() {
+  return on_battery_power_;
+}
+
+void PowerMonitorBroadcastSource::OnPowerStateChange(bool on_battery_power) {
+  on_battery_power_ = on_battery_power;
+  ProcessPowerEvent(PowerMonitorSource::POWER_STATE_EVENT);
+}
+
+void PowerMonitorBroadcastSource::OnSuspend() {
+  ProcessPowerEvent(PowerMonitorSource::RESUME_EVENT);
+}
+
+void PowerMonitorBroadcastSource::OnResume() {
+  ProcessPowerEvent(PowerMonitorSource::SUSPEND_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