Unlock Chrome when a phone with Smart Lock service is found.

components/proximity_auth/ble/bluetooth_low_energy_connection_finder.cc

 // 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 "components/proximity_auth/ble/bluetooth_low_energy_connection_finder.h"
 
 #include <string>
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
@@ skipping 136 matching lines @@
       if (remote_service_uuid_ == *iter) {
         return true;
       }
     }
   }
   return false;
 }
 
 void BluetoothLowEnergyConnectionFinder::OnCreateConnectionError(
     BluetoothDevice::ConnectErrorCode error_code) {
-  VLOG(1) << "Error creating connection";
+  VLOG(1) << "Error creating connection: " << error_code;
 }
 
 void BluetoothLowEnergyConnectionFinder::OnConnectionCreated(
     scoped_ptr<BluetoothGattConnection> connection) {
   VLOG(1) << "Connection created";
   connected_ = true;
   StopDiscoverySession();
-  connection_callback_.Run(connection.Pass());
+  if (!connection_callback_.is_null()) {
+    connection_callback_.Run(connection.Pass());
+    connection_callback_.Reset();
+  }
 }
 
 void BluetoothLowEnergyConnectionFinder::CreateConnection(
     device::BluetoothDevice* remote_device) {
   VLOG(1) << "SmartLock service found ("
           << remote_service_uuid_.canonical_value() << ")\n"
           << "device = " << remote_device->GetAddress()
           << ", name = " << remote_device->GetName();
   remote_device->CreateGattConnection(
       base::Bind(&BluetoothLowEnergyConnectionFinder::OnConnectionCreated,
                  weak_ptr_factory_.GetWeakPtr()),
       base::Bind(&BluetoothLowEnergyConnectionFinder::OnCreateConnectionError,
                  weak_ptr_factory_.GetWeakPtr()));
 }
 
 }  // namespace proximity_auth