[Bluetooth] Improve the adapter's awareness of connected devices.

device/bluetooth/bluetooth_channel_mac.h

 // Copyright 2014 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_CHANNEL_MAC_H_
 #define DEVICE_BLUETOOTH_BLUETOOTH_CHANNEL_MAC_H_
 
 #import <IOKit/IOReturn.h>
 
 #include <string>
 
 #include "base/macros.h"
 
+@class IOBluetoothDevice;
+
 namespace device {
 
 class BluetoothSocketMac;
 
 // Wraps a native RFCOMM or L2CAP channel.
 class BluetoothChannelMac {
  public:
   BluetoothChannelMac();
   virtual ~BluetoothChannelMac();
 
   // Sets the channel's owning socket to |socket|. Should only be called if the
   // socket was previously unset. Note: This can synchronously call back into
   // socket->OnChannelOpenComplete().
   virtual void SetSocket(BluetoothSocketMac* socket);
 
   // Returns the Bluetooth address for the device associated with |this|
   // channel.
-  virtual std::string GetDeviceAddress() = 0;
+  std::string GetDeviceAddress();
+
+  // Returns the Bluetooth device associated with |this| channel.
+  virtual IOBluetoothDevice* GetDevice() = 0;
 
   // Returns the outgoing MTU (maximum transmission unit) for the channel.
   virtual uint16_t GetOutgoingMTU() = 0;
 
   // Writes |data| of length |length| bytes into the channel. The |refcon| is a
   // user-supplied value that gets passed to the write callback.
   // Returns kIOReturnSuccess if the data was buffered successfully.
   // If the return value is an error condition none of the data was sent.
   // The number of bytes to be sent must not exceed the channel MTU.
   //
   // Once the data has been successfully passed to the hardware to be
   // transmitted, the socket's method OnChannelWriteComplete() will be called
   // with the |refcon| that was passed to this method.
   virtual IOReturn WriteAsync(void* data, uint16_t length, void* refcon) = 0;
 
  protected:
   BluetoothSocketMac* socket() { return socket_; }
 
  private:
   // The socket that owns |this|.
   BluetoothSocketMac* socket_;
 
   DISALLOW_COPY_AND_ASSIGN(BluetoothChannelMac);
 };
 
 }  // namespace device
 
 #endif  // DEVICE_BLUETOOTH_BLUETOOTH_CHANNEL_MAC_H_