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

extensions/browser/api/bluetooth/bluetooth_api_utils.cc

 // Copyright (c) 2012 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 "extensions/browser/api/bluetooth/bluetooth_api_utils.h"
 
 #include "base/strings/utf_string_conversions.h"
 #include "base/values.h"
 #include "device/bluetooth/bluetooth_adapter.h"
 #include "device/bluetooth/bluetooth_device.h"
@@ skipping 103 matching lines @@
   out->connecting.reset(new bool(device.IsConnecting()));
   out->connectable.reset(new bool(device.IsConnectable()));
 
   std::vector<std::string>* string_uuids = new std::vector<std::string>();
   const device::BluetoothDevice::UUIDList& uuids = device.GetUUIDs();
   for (device::BluetoothDevice::UUIDList::const_iterator iter = uuids.begin();
        iter != uuids.end(); ++iter)
     string_uuids->push_back(iter->canonical_value());
   out->uuids.reset(string_uuids);
 
-  if (device.GetInquiryRSSI() != device::BluetoothDevice::kUnknownPower)
-    out->inquiry_rssi.reset(new int(device.GetInquiryRSSI()));
+  if (device.GetInquiryRSSI())
+    out->inquiry_rssi.reset(new int(device.GetInquiryRSSI().value()));
   else
     out->inquiry_rssi.reset();
 
-  if (device.GetInquiryTxPower() != device::BluetoothDevice::kUnknownPower)
-    out->inquiry_tx_power.reset(new int(device.GetInquiryTxPower()));
+  if (device.GetInquiryTxPower())
+    out->inquiry_tx_power.reset(new int(device.GetInquiryTxPower().value()));
   else
     out->inquiry_tx_power.reset();
 }
 
 void PopulateAdapterState(const device::BluetoothAdapter& adapter,
                           AdapterState* out) {
   out->discovering = adapter.IsDiscovering();
   out->available = adapter.IsPresent();
   out->powered = adapter.IsPowered();
   out->name = adapter.GetName();
   out->address = adapter.GetAddress();
 }
 
 }  // namespace bluetooth
 }  // namespace api
 }  // namespace extensions