[CrOS Tether] Create ble_constants.h/cc, which include common constants to be shared among multiple…

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_BLE_CONSTANTS_H_

[Ryan Hansberry, 2016/12/20 05:21:09]

nit: should be CHROMEOS_COMPONENTS_TETHER_BLE_CONSTANTS_H_

[Kyle Horimoto, 2016/12/20 05:31:32]

Done.

+#define CHROMEOS_COMPONENTS_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;

[Ryan Hansberry, 2016/12/20 05:21:09]

Will this need to be used anywhere else in the future? I don't mind it being
here, I'm just curious.

[Kyle Horimoto, 2016/12/20 05:31:32]

Yes, it will be used by the scanner and advertiser.

+
+// The service UUID used for BLE advertisements.
+extern const char kAdvertisingServiceUuid[];
+
+}  // namespace tether
+
+}  // namespace chromeos
+
+#endif  // CHROMEOS_COMPONENTS_BLE_CONSTANTS_H_