bluetooth: Return int8_t and use -128 for unknown tx power.

third_party/WebKit/Source/modules/bluetooth/BluetoothAdvertisingData.cpp

 // 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 "modules/bluetooth/BluetoothAdvertisingData.h"
 
 namespace blink {
 
 namespace {
-// TODO(ortuno): RSSI Unknown and Tx Power Unknown should have different
-// values. Add kUnknownTxPower when implemented: http://crbug.com/551572
-const int kUnknownPower = 127;
+    const int8_t kUnknownRSSI = 127;

[scheib, 2016/05/04 01:18:38]

Comment explaining the source of the numbers (cite spec as in
bluetooth_device.h)

[ortuno, 2016/05/04 16:44:12]

We removed BluetoothAdvertisingData so no need to repeat the value here.

+    const int8_t kUnknownTxPower = -128;
 } // namespace
 
 BluetoothAdvertisingData* BluetoothAdvertisingData::create(int8_t txPower, int8_t rssi)
 {
     return new BluetoothAdvertisingData(txPower, rssi);
 }
 
 int8_t BluetoothAdvertisingData::txPower(bool& isNull)
 {
-    if (m_txPower == kUnknownPower) {
+    if (m_txPower == kUnknownTxPower) {
         isNull = true;
     }
     return m_txPower;
 }
 
 int8_t BluetoothAdvertisingData::rssi(bool& isNull)
 {
-    if (m_rssi == kUnknownPower) {
+    if (m_rssi == kUnknownRSSI) {
         isNull = true;
     }
     return m_rssi;
 }
 
 BluetoothAdvertisingData::BluetoothAdvertisingData(int8_t txPower, int8_t rssi)
     : m_txPower(txPower)
     , m_rssi(rssi)
 {
 }
 
 } // namespace blink