chromeos: Add support for the battery status API on chromeos.

content/browser/battery_status/battery_status_message_filter.h

Index: content/browser/battery_status/battery_status_message_filter.h
diff --git a/content/browser/battery_status/battery_status_message_filter.h b/content/browser/battery_status/battery_status_message_filter.h
new file mode 100644
index 0000000000000000000000000000000000000000..76bc79e3b42c75421b1b68e4ab91060412c83c20
--- /dev/null
+++ b/content/browser/battery_status/battery_status_message_filter.h
@@ -0,0 +1,42 @@
+// Copyright (c) 2012 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_BROWSER_BATTERY_STATUS_BATTERY_STATUS_MESSAGE_FILTER_H_
+#define CONTENT_BROWSER_BATTERY_STATUS_BATTERY_STATUS_MESSAGE_FILTER_H_
+
+#include <list>
+
+#include "content/public/browser/battery_status_provider.h"
+#include "content/public/browser/browser_message_filter.h"
+
+namespace content {
+
+class BatteryStatusMessageFilter : public content::BrowserMessageFilter {
+ public:
+  BatteryStatusMessageFilter();
+
+  void SendUpdates(const content::PowerSupplyStatus& power_status);
+
+ private:
+  virtual ~BatteryStatusMessageFilter();
+
+  void OnStartUpdating(int render_view_id);
+  void OnStopUpdating(int render_view_id);
+
+  // content::BrowserMessageFilter implementation.
+  virtual bool OnMessageReceived(const IPC::Message& message,
+                                 bool* message_was_ok) OVERRIDE;
+
+  // The list of RenderViews that want battery status updates.
+  std::list<int> notify_updates_;
+
+  class PowerManagerObserver;
+  scoped_ptr<PowerManagerObserver> observer_;
+
+  DISALLOW_COPY_AND_ASSIGN(BatteryStatusMessageFilter);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_BROWSER_BATTERY_STATUS_BATTERY_STATUS_MESSAGE_FILTER_H_