Created multi-process-friendly PowerMonitor interface.

content/common/power_monitor_message_filter.h

Index: content/common/power_monitor_message_filter.h
diff --git a/content/common/power_monitor_message_filter.h b/content/common/power_monitor_message_filter.h
new file mode 100644
index 0000000000000000000000000000000000000000..3d8a732fa576f1bdadfa14c8d87c62d900ede81b
--- /dev/null
+++ b/content/common/power_monitor_message_filter.h
@@ -0,0 +1,35 @@
+// 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_MESSAGE_FILTER_H_
+#define CONTENT_COMMON_POWER_MONITOR_MESSAGE_FILTER_H_
+
+#include "ipc/ipc_channel.h"
+#include "ipc/ipc_channel_proxy.h"
+
+namespace content {
+
+class PowerMonitorClient;
+
+class PowerMonitorMessageFilter : public IPC::ChannelProxy::MessageFilter {
+ public:
+  PowerMonitorMessageFilter();

[Ken Russell (switch to Gerrit), 2013/06/24 22:54:38]

It seems confusing to me that the PowerMonitorMessageFilter retrieves the
singleton PowerMonitorClient itself, and callers also fetch the singleton
PowerMonitorClient and add themselves as observers to it. It would be more
understandable in my opinion if the PowerMonitorClient were passed in to the
constructor by the caller.

[bajones, 2013/06/25 18:33:34]

I agree. This entire class is being removed, however, so it's a moot point.

+
+  virtual bool OnMessageReceived(const IPC::Message& message) OVERRIDE;
+
+ private:
+  virtual ~PowerMonitorMessageFilter();
+
+  void OnPowerStateChange(bool on_battery_power);
+  void OnSuspend();
+  void OnResume();
+
+  PowerMonitorClient* client_;
+
+  DISALLOW_COPY_AND_ASSIGN(PowerMonitorMessageFilter);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_COMMON_POWER_MONITOR_MESSAGE_FILTER_H_