bluetooth: Implement RSSI and Tx Power on macOS and Android

device/bluetooth/bluetooth_adapter_mac.mm

Index: device/bluetooth/bluetooth_adapter_mac.mm
diff --git a/device/bluetooth/bluetooth_adapter_mac.mm b/device/bluetooth/bluetooth_adapter_mac.mm
index ef4a20dee2da1156e992a84add68576b47755754..eb54042f88d7034d338a5f56e41095feb5d08f18 100644
--- a/device/bluetooth/bluetooth_adapter_mac.mm
+++ b/device/bluetooth/bluetooth_adapter_mac.mm
@@ -539,8 +539,19 @@ void BluetoothAdapterMac::LowEnergyDeviceUpdated(
                              std::vector<uint8_t>(bytes, bytes + length));
   }
 
-  device_mac->UpdateAdvertisementData(std::move(advertised_uuids),
-                                      std::move(service_data_map));
+  // Get Tx Power.
+  base::Optional<int8_t> clamped_tx_power;
+  NSNumber* tx_power =
+      [advertisement_data objectForKey:CBAdvertisementDataTxPowerLevelKey];
+  clamped_tx_power =
+      tx_power == nil ? base::nullopt

[Jeffrey Yasskin, 2016/08/24 04:32:02]

Either make this the initialization of the variable, and keep the ?:, or write
this assignment as an if statement, which would also let you remove the
make_optional<> call.

[ortuno, 2016/08/24 21:29:09]

Done. hmm I wonder why I declared the variable up there...

+                      : base::make_optional<int8_t>(
+                            BluetoothDevice::ClampPower([tx_power intValue]));
+
+  device_mac->UpdateAdvertisementData(
+      BluetoothDevice::ClampPower(rssi), std::move(advertised_uuids),
+      std::move(service_data_map),
+      clamped_tx_power ? &clamped_tx_power.value() : nullptr);
 
   if (is_new_device) {
     std::string device_address =