Add bluetooth device type icons on MD system tray.

device/bluetooth/bluetooth_common.h

 // Copyright 2016 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 DEVICE_BLUETOOTH_BLUETOOTH_TYPES_H_
 #define DEVICE_BLUETOOTH_BLUETOOTH_TYPES_H_
 
 #include "device/bluetooth/bluetooth_export.h"
 
 // This file is for enums and small types common to several
 // parts of bluetooth.
 
 namespace device {
 
 // Devices and adapters can support a number of transports,
 // and bluetooth hosts can scan for devices based on the
 // transports they support.
 enum BluetoothTransport : uint8_t {
   BLUETOOTH_TRANSPORT_INVALID = 0x00,
   // Valid transports are given as a bitset.
   BLUETOOTH_TRANSPORT_CLASSIC = 0x01,
   BLUETOOTH_TRANSPORT_LE = 0x02,
   BLUETOOTH_TRANSPORT_DUAL =
       (BLUETOOTH_TRANSPORT_CLASSIC | BLUETOOTH_TRANSPORT_LE)
 };
 
+// Possible values that may be returned by BluetoothDevice::GetDeviceType(),
+// representing different types of bluetooth device that we support or are aware
+// of decoded from the bluetooth class information.
+enum class BluetoothDeviceType {
+  UNKNOWN,

[fukino, 2016/10/05 06:34:45]

BLUETOOTH_DEVICE_TYPE_UNKNOWN is more consistent with values of
BluetoothTransport in this file.

However, it doesn't look common in chromium to add prefixes for enum class
members, so I simply used "UNKNOWN", "COMPUTER", etc...

[ortuno, 2016/10/05 06:59:11]

Makes sense. I think we added the prefix to BluetoothTransport because it's only
an enum rather than an enum class.

+  COMPUTER,
+  PHONE,
+  MODEM,
+  AUDIO,
+  CAR_AUDIO,
+  VIDEO,
+  PERIPHERAL,
+  JOYSTICK,
+  GAMEPAD,
+  KEYBOARD,
+  MOUSE,
+  TABLET,
+  KEYBOARD_MOUSE_COMBO
+};
+
 }  // namespace device
 
 #endif  // DEVICE_BLUETOOTH_BLUETOOTH_TYPES_H_