[CrOS Tether] Create BleScanner, a class which scan BLE advertisements and identifies nearby device…

chromeos/components/tether/ble_constants.h

 // Copyright 2016 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 CHROMEOS_COMPONENTS_TETHER_BLE_CONSTANTS_H_
 #define CHROMEOS_COMPONENTS_TETHER_BLE_CONSTANTS_H_
 
 #include <string>
 
 namespace chromeos {
 
 namespace tether {
 
 // The maximum number of devices to which to advertise concurrently. If more
 // than this number of devices are registered, other advertisements must be
 // stopped before new ones can be added.
 //
 // Note that this upper limit on concurrent advertisements is imposed due to a
 // hardware limit of advertisements (many devices have <10 total advertisement
 // slots).
-extern const int kMaxConcurrentAdvertisements;
+extern const uint8_t kMaxConcurrentAdvertisements;
 
 // The service UUID used for BLE advertisements.
 extern const char kAdvertisingServiceUuid[];
 
 }  // namespace tether
 
 }  // namespace chromeos
 
 #endif  // CHROMEOS_COMPONENTS_TETHER_BLE_CONSTANTS_H_