Implement create attribute API functions for BTLE.

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 189 matching lines @@
 }
 
 void BluetoothAdapterMac::RegisterAdvertisement(
     std::unique_ptr<BluetoothAdvertisement::Data> advertisement_data,
     const CreateAdvertisementCallback& callback,
     const CreateAdvertisementErrorCallback& error_callback) {
   NOTIMPLEMENTED();
   error_callback.Run(BluetoothAdvertisement::ERROR_UNSUPPORTED_PLATFORM);
 }
 
+BluetoothLocalGattService* BluetoothAdapterMac::GetGattService(
+    const std::string& identifier) const {
+  return nullptr;
+}
+
 void BluetoothAdapterMac::ClassicDeviceFound(IOBluetoothDevice* device) {
   ClassicDeviceAdded(device);
 }
 
 void BluetoothAdapterMac::ClassicDiscoveryStopped(bool unexpected) {
   if (unexpected) {
     DVLOG(1) << "Discovery stopped unexpectedly";
     num_discovery_sessions_ = 0;
     MarkDiscoverySessionsAsInactive();
   }
@@ skipping 391 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