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

content/common/battery_status_messages.h

Index: content/common/battery_status_messages.h
diff --git a/content/common/battery_status_messages.h b/content/common/battery_status_messages.h
new file mode 100644
index 0000000000000000000000000000000000000000..4579333fafe3a2d05880d59de77eb763552a89a4
--- /dev/null
+++ b/content/common/battery_status_messages.h
@@ -0,0 +1,26 @@
+// 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.
+
+// IPC messages for battery status api.
+// Multiply-included message file, hence no include guard.
+
+
+#include "ipc/ipc_message_macros.h"
+
+#define IPC_MESSAGE_START BatteryStatusMsgStart
+
+// Messages sent from the renderer to the browser.
+
+// Asks the browser process to start or stop sending battery status updates.
+IPC_MESSAGE_CONTROL1(BatteryStatusHostMsg_StartUpdating,
+                     int /* render_view_id */)
+
+IPC_MESSAGE_CONTROL1(BatteryStatusHostMsg_StopUpdating,
+                     int /* render_view_id */)
+
+// Messages sent from the browser to the renderer.
+
+// Sends the battery-status update to the renderer. The message payload includes
+// a blot that should be cast to WebBatteryStatus.
+IPC_MESSAGE_ROUTED0(BatteryStatusMsg_Updated)