Expose TxPower for bluetooth devices during discovery

device/bluetooth/bluetooth_low_energy_device_mac.mm

 // Copyright 2015 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_low_energy_device_mac.h"
 
 #import <CoreFoundation/CoreFoundation.h>
 
 #include "base/mac/scoped_cftyperef.h"
 #include "base/mac/sdk_forward_declarations.h"
@@ skipping 129 matching lines @@
 }
 
 BluetoothDevice::UUIDList BluetoothLowEnergyDeviceMac::GetUUIDs() const {
   return std::vector<device::BluetoothUUID>();
 }
 
 int16 BluetoothLowEnergyDeviceMac::GetInquiryRSSI() const {
   return kUnknownPower;
 }
 
+int16 BluetoothLowEnergyDeviceMac::GetInquiryTxPower() const {
+  NOTIMPLEMENTED();
+  return kUnknownPower;
+}
+
 bool BluetoothLowEnergyDeviceMac::ExpectingPinCode() const {
   return false;
 }
 
 bool BluetoothLowEnergyDeviceMac::ExpectingPasskey() const {
   return false;
 }
 
 bool BluetoothLowEnergyDeviceMac::ExpectingConfirmation() const {
   return false;
@@ skipping 72 matching lines @@
     // When -[CBPeripheral identifier] is available.
     NSUUID* uuid = [peripheral identifier];
     NSString* uuidString = [uuid UUIDString];
     return base::SysNSStringToUTF8(uuidString);
   }
 
   base::ScopedCFTypeRef<CFStringRef> str(
       CFUUIDCreateString(NULL, [peripheral UUID]));
   return SysCFStringRefToUTF8(str);
 }