Created multi-process-friendly PowerMonitor interface.

content/common/power_monitor_broadcast_source.h

+// 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.
+
+#ifndef CONTENT_COMMON_POWER_MONITOR_BROADCAST_SOURCE_H_
+#define CONTENT_COMMON_POWER_MONITOR_BROADCAST_SOURCE_H_
+
+#include "base/power_monitor/power_monitor_source.h"
+
+#include "ipc/ipc_channel.h"
+#include "ipc/ipc_channel_proxy.h"
+
+namespace content {
+
+class PowerMonitorBroadcastSource : public base::PowerMonitorSource {
+ public:
+  PowerMonitorBroadcastSource();
+  virtual ~PowerMonitorBroadcastSource();
+
+  IPC::ChannelProxy::MessageFilter* MessageFilter();
+
+ private:
+  friend class PowerMonitorMessageFilter;
+
+  class PowerMessageFilter : public IPC::ChannelProxy::MessageFilter {
+   public:
+    explicit PowerMessageFilter(PowerMonitorBroadcastSource* source);
+
+    virtual bool OnMessageReceived(const IPC::Message& message) OVERRIDE;
+
+   private:
+    friend class base::RefCounted<PowerMessageFilter>;
+
+    virtual ~PowerMessageFilter();
+
+    void OnPowerStateChange(bool on_battery_power);
+    void OnSuspend();
+    void OnResume();
+
+    PowerMonitorBroadcastSource* source_;

[vandebo (ex-Chrome), 2013/07/02 22:53:12]

How are we sure that this pointer is still valid?  At the least it needs a
comment.  Couldn't you just use PowerMonitor::Source() though?

+
+    DISALLOW_COPY_AND_ASSIGN(PowerMessageFilter);
+  };
+
+  virtual bool IsBatteryPower() OVERRIDE;
+
+  void OnPowerStateChange(bool on_battery_power);
+  void OnSuspend();
+  void OnResume();
+
+  bool on_battery_power_;
+  scoped_refptr<PowerMessageFilter> message_filter_;
+};
+
+}  // namespace content
+
+#endif  // CONTENT_COMMON_POWER_MONITOR_MESSAGE_FILTER_H_