add device notification to Mac

content/browser/device_monitor_mac.h

Index: content/browser/device_monitor_mac.h
diff --git a/content/browser/device_monitor_mac.h b/content/browser/device_monitor_mac.h
new file mode 100644
index 0000000000000000000000000000000000000000..2495761e20250780b75bb96caf52998b62a80320
--- /dev/null
+++ b/content/browser/device_monitor_mac.h
@@ -0,0 +1,34 @@
+// 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_DEVICE_MONITOR_MAC_H_
+#define CONTENT_BROWSER_DEVICE_MONITOR_MAC_H_
+
+#include <IOKit/IOKitLib.h>
+
+#include "base/basictypes.h"
+#include "base/system_monitor/system_monitor.h"
+
+namespace content {
+
+class DeviceMonitorMac {
+ public:
+  DeviceMonitorMac();
+  ~DeviceMonitorMac();
+
+ private:
+  void RegisterVideoCallbacks(IONotificationPortRef port);
+  void RegisterAudioCallbacks(IONotificationPortRef port);
+
+  static void VideoDeviceChangedCallback(void *context, io_iterator_t devices);
+  static void AudioDeviceChangedCallback(void *context, io_iterator_t devices);
+
+  void NotifyDeviceChanged(base::SystemMonitor::DeviceType type);
+
+  DISALLOW_COPY_AND_ASSIGN(DeviceMonitorMac);
+};
+
+}  // namespace content
+
+#endif  // CONTENT_BROWSER_DEVICE_MONITOR_MAC_H_