Delete unused BluetoothAudioSink code.

device/bluetooth/bluetooth_adapter_mac.mm

 // Copyright 2013 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.
 
 #include "device/bluetooth/bluetooth_adapter_mac.h"
 
 #import <IOBluetooth/objc/IOBluetoothDevice.h>
 #import <IOBluetooth/objc/IOBluetoothHostController.h>
 #include <stddef.h>
 
@@ skipping 177 matching lines @@
 void BluetoothAdapterMac::CreateL2capService(
     const BluetoothUUID& uuid,
     const ServiceOptions& options,
     const CreateServiceCallback& callback,
     const CreateServiceErrorCallback& error_callback) {
   scoped_refptr<BluetoothSocketMac> socket = BluetoothSocketMac::CreateSocket();
   socket->ListenUsingL2cap(
       this, uuid, options, base::Bind(callback, socket), error_callback);
 }
 
-void BluetoothAdapterMac::RegisterAudioSink(
-    const BluetoothAudioSink::Options& options,
-    const AcquiredCallback& callback,
-    const BluetoothAudioSink::ErrorCallback& error_callback) {
-  NOTIMPLEMENTED();
-  error_callback.Run(BluetoothAudioSink::ERROR_UNSUPPORTED_PLATFORM);
-}
-
 void BluetoothAdapterMac::RegisterAdvertisement(
     std::unique_ptr<BluetoothAdvertisement::Data> advertisement_data,
     const CreateAdvertisementCallback& callback,
     const AdvertisementErrorCallback& error_callback) {
   NOTIMPLEMENTED();
   error_callback.Run(BluetoothAdvertisement::ERROR_UNSUPPORTED_PLATFORM);
 }
 
 BluetoothLocalGattService* BluetoothAdapterMac::GetGattService(
     const std::string& identifier) const {
@@ skipping 430 matching lines @@
   std::string device_address =
       BluetoothLowEnergyDeviceMac::GetPeripheralHashAddress(peripheral);
   DevicesMap::const_iterator iter = devices_.find(device_address);
   if (iter == devices_.end()) {
     return nil;
   }
   return static_cast<BluetoothLowEnergyDeviceMac*>(iter->second);
 }
 
 }  // namespace device