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

device/bluetooth/bluez/bluetooth_device_bluez.h

 // Copyright 2013 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 DEVICE_BLUETOOTH_BLUEZ_BLUETOOTH_DEVICE_BLUEZ_H_
 #define DEVICE_BLUETOOTH_BLUEZ_BLUETOOTH_DEVICE_BLUEZ_H_
 
 #include <stdint.h>
 
 #include <memory>
 #include <string>
 
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/memory/weak_ptr.h"
+#include "base/optional.h"
 #include "base/sequenced_task_runner.h"
 #include "dbus/object_path.h"
 #include "device/bluetooth/bluetooth_device.h"
 #include "device/bluetooth/bluetooth_export.h"
 #include "device/bluetooth/dbus/bluetooth_device_client.h"
 #include "device/bluetooth/dbus/bluetooth_gatt_service_client.h"
 
 namespace device {
 class BluetoothSocketThread;
 }  // namespace device
@@ skipping 21 matching lines @@
   uint16_t GetVendorID() const override;
   uint16_t GetProductID() const override;
   uint16_t GetDeviceID() const override;
   uint16_t GetAppearance() const override;
   bool IsPaired() const override;
   bool IsConnected() const override;
   bool IsGattConnected() const override;
   bool IsConnectable() const override;
   bool IsConnecting() const override;
   UUIDList GetUUIDs() const override;
-  int16_t GetInquiryRSSI() const override;
-  int16_t GetInquiryTxPower() const override;
+  base::Optional<int8_t> GetInquiryRSSI() const override;
+  base::Optional<int8_t> GetInquiryTxPower() const override;
   bool ExpectingPinCode() const override;
   bool ExpectingPasskey() const override;
   bool ExpectingConfirmation() const override;
   void GetConnectionInfo(const ConnectionInfoCallback& callback) override;
   void Connect(device::BluetoothDevice::PairingDelegate* pairing_delegate,
                const base::Closure& callback,
                const ConnectErrorCallback& error_callback) override;
   void SetPinCode(const std::string& pincode) override;
   void SetPasskey(uint32_t passkey) override;
   void ConfirmPairing() override;
@@ skipping 53 matching lines @@
       scoped_refptr<device::BluetoothSocketThread> socket_thread);
   ~BluetoothDeviceBlueZ() override;
 
   // bluez::BluetoothGattServiceClient::Observer overrides.
   void GattServiceAdded(const dbus::ObjectPath& object_path) override;
   void GattServiceRemoved(const dbus::ObjectPath& object_path) override;
 
   // Called by dbus:: on completion of the D-Bus method call to get the
   // connection attributes of the current connection to the device.
   void OnGetConnInfo(const ConnectionInfoCallback& callback,
-                     int16_t rssi,
-                     int16_t transmit_power,
-                     int16_t max_transmit_power);
+                     const base::Optional<int16_t>& rssi,
+                     const base::Optional<int16_t>& transmit_power,
+                     const base::Optional<int16_t>& max_transmit_power);
   void OnGetConnInfoError(const ConnectionInfoCallback& callback,
                           const std::string& error_name,
                           const std::string& error_message);
 
   // Internal method to initiate a connection to this device, and methods called
   // by dbus:: on completion of the D-Bus method call.
   void ConnectInternal(bool after_pairing,
                        const base::Closure& callback,
                        const ConnectErrorCallback& error_callback);
   void OnConnect(bool after_pairing, const base::Closure& callback);
@@ skipping 67 matching lines @@
   // Note: This should remain the last member so it'll be destroyed and
   // invalidate its weak pointers before any other members are destroyed.
   base::WeakPtrFactory<BluetoothDeviceBlueZ> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(BluetoothDeviceBlueZ);
 };
 
 }  // namespace bluez
 
 #endif  // DEVICE_BLUETOOTH_BLUEZ_BLUETOOTH_DEVICE_BLUEZ_H_